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2019-10-28-minutes-public-works-study-session
KITTITAS COUNTY COMMISSIONERS Public Works Study Session Regular Meeting Monday October 28, 2019 -1:30 PM Commissioners' Auditorium 205 West 5th Room 109 - Ellensburg 1. Call to Order 2.2019 Construction Update 3. University Way and Reecer Creek Signal Discussion 4. Lick Creek Update S. Other business 6. Adjourn Created on 10/24/2019 6:29:30 AM KITTITAS COUNTY PUBLIC WORKS STUDY SESSION MINUTES COMMISSIONERS' AUDITORIUM, 205 WEST STH ROOM 109 - ELLENSBURG Regular Meeting MONDAY 1.:30 PM OCTOBER 28, 2019 Board members present: Chairman Cory Wright, Vice -Chairman Brett Wachsmith, Commissioner Laura Osiadacz Others: Mark Cook and Candie Leader, Public Works; Calvana Carper, Dan Carlson, Lindsey Ozbolt, Community Development Services; Lisa Young, Human Resources and Three (3) Members of the Public At 1:31 pm Chairman Cory Wright opened the Public Works Study Session. Mark Cook stated it was his understanding that Agenda Item 43 - University Way and Reecer Signal Discussion is being removed from discussion. 2019 CONSTRUCTION UPDATE Mark Cook gave background on the Big Boulder Bridge Replacement Project and adding that the temporary bridge is in place. Mark Cook continued that discussions with KPFF to draft a task order for the redesign the permanent bridge. Mark Cook added the cost is estimated at sixty thousand dollars ($60,000) with work to be performed in 2020. Mark Cook stated that the Story Creek culvert project is complete. Mark Cook gave background on the project adding that this project is the first of the Federal Highway Administration grants that were awarded to Kittitas County for improvement of hydraulics in the Teanaway. Mark Cook added that the project got off to a slow start; however, the contractor delivered the project on time and on budget. Mark Cook gave background on Weihl Road and the court decision to void the Road Improvement District that was formed to assist in the cost of the project. Mark Cook stated that guardrail was to be installed today and some striping needs to be completed then the project can be closed out. Mark Cook explained the engineering on the wall that was placed and that the original design was rejected. Mark Cook continued that the bid included the wall and materials as a unit and this left the contractor with more material than originally bid. Mark Cook added that an additional conversation will need to be had about a possible cost adjustment for this item. Mark Cook commented that the contractor did a good job on the project. Mark Cook mentioned that the Fairview Road project is pending right of way negotiation and this project is scheduled for 2020. Mark Cook stated that the signal at Reecer Creek and University Way 2019-10-28 MINUTES design may be completed by January and the City of Ellensburg has a link on their website on the project that is hosted by the consultant working on the project - LICK CREEK UPDATE Mark Cook stated that staff has been communicating with the Board of County Commissioners (BOCC) on this project as new information is received. Mark Cook continued that this is the second of two projects with the Federal Highway Administration for hydraulics in the Teanaway. Mark Cook added that this project has stalled due to issues regarding reconnecting to the river which was the county's preferred plan. Mark Cook commented that there has been opposition from the residents in the area and Washington State Department of Fish and Wildlife (WDFW) requested an additional study on the project. Mark Cook stated that staff spent ten (10) months analyzing and collecting data and staff included the technical memo with this briefing for BOCC review. Mark Cook added that additional modeling was done with culverts in the area open and plugged to show any adverse impacts and after meeting with WDFW it is clear that the path forward is to do a bridge replacement only. Discussion was held. Commissioner Laura Osiadacz commented that she would hate to see all the time and effort on this project go to waste. Mark Cook added that the county had a committed path on this project but it is not going to work so it's time move ahead. Meeting adjourned at 1:48 pm 2019-10-28 MINUTES KITTITAS COUNTY COMMISSIONERS KITTITAS COUNTY, WASHINGTON Cory Wright, Chairman KITTITAS COUNTY DEPARTMENT OF PUBLIC WORKS PUBLIC WORKS — BOARD OF COUNTY COMMISSIONERS STUDY SESSION STAFF REPORT STUDY SESSION DATE: October 28, 2419 TOPIC: 2019 Construction Update ACTION REQUESTED: Advisory — No Action Required LEAD STAFF: Mark R. Cook RECOMMENDATION: Advisory briefing — no action required. BRIEFING SUMMARY: • Big Boulder temporary bridge is complete • Story Creek culvert replacement is complete • Wiehl Road completes the week of 10/28/2019 • Bar 14 turnaround designs are complete and acquisition discussions have begun BACKGROUND: All 2019 construction projects have been delivered with the exception of Fairview Road. Big Boulder final bridge installation is postponed until summer 2020, owing to the lack of bidder response. Wiehl Road road improvement district was invalidated by Superior Court and Public Works did not appeal the decision. DISCUSSION: Fairview Road is delayed owing to the inability of concluding property acquisition prior to meeting permitting deadlines. Resolution with the impacted property action will resume this winter. Failure to reach a compromise on land value will result in PW pursuing a pavement break project for 2020 construction. A redesigned final bridge installation project for Big Boulder is planned for the remainder of 2019. PW has completed negotiations with KPFF to redesign the final bridge for 2020 construction. Wiehl Road completes guardrail installation this week. The road was paved two weeks ago along with final plantings and bank restoration efforts. PW is currently proposing to cover the cost of construction by using the "Gravel Road Upgrade" program. Approximately $150,000 per year is budgeted to upgrade gravel roads to chip seal. Using Page 1 of 5 PUBLIC WORKS BOARD OF COUNTY Co, LvM- SSIONERS WORK SESSION STAFF REPORT this funding line time for Wiehl Road upgrades will obligate approximately four years of this program's financing. FISCAL RvIPACTS: • Story on time and on budget. • Wiehl Road on time and on budget (Granite over on wall fill item). • Big Boulder temporary bridge on time and on budget. $228,000 has been spent on the design phase of the project. $48,191 was spent on the temporary 40 foot bridge that will go into PW inventory upon installation of the permanent bridge. • Fairview design is complete and on the shelf pending property acquisition resolution. $222,025 has been spent on the design phase of the project. ATTACHMENTS: Exhibit 1: Big Boulder photo Exhibit 2: Story Creek photo Exhibit 3: Wiehl Road photo Page 2 of 5 PUBLIC WORKS BOARD OF COUNTY CONINIISSIONERS WORK SESSION STAFF REPORT EX IIBIT 1: BIG BOULDER TEMPORARY BRIDGE PHOTO Page 3 of 5 PUBLIC WORKS BOARD OF COUNTY COQ jvuSSIONERS WORK SESSION STAFF REPORT SYS Yi �.•. � r � [+r C;d -Y. VL. x, 1: � •� S'I �k �.,�f`• � '"a � 't�..ti�R �i }fit"t� �,a - i1 A k �. }�,,,� mak, Y i �i jty�i Y • IL 4 . INK, A a r �''•kG�';.y i �i9. ! �'i,•�,,. � r }IP � • r f 2 t _ I �y �,� # � �•"� - } F •e. r �� �FI ' f' ra EXHIBIT 2: STORY CREEK CULVERT PHOTO Page 4 of 5 PUBLIC WORKS BOARD OF COUNTY COMNUSSIONERS WORK SESSION STAFF REPORT t' EXHIBIT 3: WIEHL ROAD PHOTO Page 5 of 5 PUBLIC WORKS BOARD OF COUNTY COMI��IISSIONERS WORK SESSION STAFF REPORT oj. KITTITAS COUNTY DEPARTMENT OF PUBLIC WORKS PUBLIC WORKS — BOARD OF COUNTY COAUMSSIONERS STUDY SESSION STAFF REPORT STUDY SESSION DATE: October 28, 2019 TOPIC: University Way and Reecer Creek Road Signal ACTION REQUESTED: Direct Staff on Construction Funding LEAD STAFF: Mark R. Cook RECOMMENDATION: Direct staff on evaluating grant funding options for constructing funding the signal. BRIEFING SUMMARY: • Roundabout contribution in 2016 for approximately $445,000 ($228,765 final cost - EXHIBIT 1). • University Way bridge repairs cost $239,116. • Public Works (PW) is currently designing a traffic signal for the University Way/Reecer Creek Road intersection ($149,000 is allocated for design). • Project website is live. • Design is on schedule. • Recent City approvals of area land use no force construction of the signal prior to solid waste transfer station construction. BACKGROUND: In 2016, PW stepped in to fund the remainder of the roundabout at the intersection of Dollar Way/University Way. As a condition of financial support, PW secured a commitment from the City of Ellensburg to annex Currier Creek Estates and University Way. In 2017, PW designed improvements to the University Way Bridge over BNSF railroad. The improvements were constructed in 2018 for a cost of $239,116. Recently, the City approved a truck fueling facility on Dollar Way that furthers degrades the service level of the intersection (University/Reecer). Now Solid Waste and PW propose collocating and the traffic impact forecasts further deterioration of intersection service level. DISCUSSION: The estimated cost to construct the signal at University and Reecer is approximately $500,000. Given that PW has invested approximately $616,881 in University Way improvements and we are no closer to annexation, it might be time to request repayment Pagel of 3 PUBLIC WORKS BOARD OF COUNTY COMNIISSIONERS WORK SESSION STAFF REPORT from the City for roundabout construction and abandon our request for annexing Currier Creek Estates. The $228,765 owed to the County will significantly retire the cost of the signal at University and Reecer. The ongoing moving target for improvements costs to University Way required by the City suggests that PW is ill prepared to continue with the requested annexation of University Way and Currier Creek Estates. The inability of the County to secure the requested annexation from the City of Ellensburg suggests larger dysfunction between the two organizations. If the Board of County Commissioners elects to cancel its annexation request, PW recommends revisiting all proposed projects in Ellensburg UGA for possible investment. This will potentially remove Bender Road and Sanders Road from the County's six year transportation pian. It might also be time to revisit the time money and effort the County spends annually chip sealing City streets. FISCAL IMPACTS: Approximately $616,881 has been spent improving University Way. Another $500,000 is likely required completing the mandatory construction of the traffic signal at University/Reecer. ATTACHMENTS: Exhibit 1: Roundabout Agreement Page 2 of 3 PUBLIC WORKS BOARD OF COUNTY COMMISSIONERS WORK SESSION STAFF REPORT EXMIT I: ROUNDABOUT AGREEMENT Page 3 of 3 PUBLIC WORKS BOARD OF COUNTY CONMSSIONERS WORK SESSION STAFF REPORT COUNTY RESOLMON No.: 20.07��q AND j WsDO.F')w-,th adiodonof ee all thra %0s. . ..... .. ejuri WHERE.A$,.:the.lnted.o.cfd:Cooperafion AcUbhur h.&Mdd ih:Chaptor-,30.34 R -CW pmvides,a:vehicle:far:rap pe,r 6n:lx P0 =" VMOf the - W� aril .... ... fi 9dbdivW6hi: S ;m .... .. .o . ..... artidpp�gin-fundin..... & stk* highwaypig*ement. prgjects �u sua tAbl��r 3635:RCW;:aiid W.- : ..... the I MREAS�: tb.e c 0— .... .y PoLm.h.c....0 ceps €t improypment oftheir respectivetoa&W-dys to mainWn:ap.propnate:.Icvels,of-sem;:'cc on the arteries roadway sysm . 'and Vff!MA-$,-t'he;WSPO.T.ii&ntified:the :int,crise iztion.-of H -i- . 9T ghwa.. tSri jversify :'*Ay I and associated.rami Wbrkon-Ti "td9- e Wio:bc-aprImty:fosmaintm llhg those levels:,ofsavicc- =d 'WHEREAS, thetity has corn rmftted-$00A00:to-ihe Prqj.tct:i-u-bq.. paio-fton.i Trafft - c .... .... .. .... 10*&t Fed: fim&oor��: w. C-44,04."LOSOa :: d. -withV8DOT-In -Ag.=—-htGC.B:242-9-;:awd pme. � pf's. WHF,REAS,:TheWSDOTptepam..dplans and i5aticiicdcom.pe of "s Tri "b'd -ah'idthe ld.w. bid- forthe: vorktxu ed thefunda'v. ai ble-forthe prqj&03�a and Bettlirau islo. C,djhplttiQn. NO.W-,;-TT.A.!RR9PORlEl, TI'M:BQAgD-OF COUNTY CQMIMI.SSIQNER.S,:AN..D THE LF.rY�C.?UNC !L.:OF'T-.ti.E.,.Crf.Y-.:OF::E.LLEN.S.B.U-RG:I:' w ... ... RMOM AS:FOUOW.S: ofA $4-45: o.Upljortdf 'the. WSDOT:Proje.ct s4bjpqto:tlie folloWing. toinidetiatibiw Page; 2 pf..5 &E-CTTON2....: The. County is currently under comtacvto repair a: pordon of aod� ington Li .3 A d ministratiow: Both -the, Countyand the: C*.vAll pasa.an -enab- ling; .. . ....... . - :OX agrft. to -the .t - t by Ment dtai su "t aWpment,. Nge.3 of.$ Pasgdd:and adopW by -the C.It,Y. CoulfteiLof-the City of -Ellensburg, this -A Of CITY OF EILE14S:BitJW6:. . ..... ....... BOA": OF.COUNTY COMWSSIONERS Attest; ....... . El CIP& of thLe B.Par.d.-Adie Njopy* 34.chholk PW 4:ofl: EjffiibitOnt-- Mop :Dopicfiftg:.P.repos.odAmiexationArea Page, Sofs, 1Y3=h;27yLoi. 7�?�+i� T�.e�4, �CQLit]t City Qerk. En.c. KITTITAS COUNTY DEPARTMENT OF PUBLIC WORKS PUBLIC WORKS — BOARD OF COUNTY COMMISSIONERS STUDY SESSION STAFF REPORT STUDY SESSION DATE: October 28, 2019 TOPIC: Lick Creek Update ACTION REQUESTED: Informational — No Action Required LEAD STAFF: Mark R. Cook RECOMMENDATION: Continue efforts connecting Lick Creek to the Teanaway River • Recently, Public Works (PW) completed a flood study on Teanaway Road resulting from culvert replacement at Lick Creek (EXHIBIT 1). • The study was required to define adverse impact for Washington State Department of Fish and Wildlife (WDFW) decision making. • PW desires connecting Lick Creek to the Teanaway River. A local resident is opposed to making the connection. • Adverse impact is predicted by replacing the culverts with the proposed bridge and maintaining creek flow in roadside ditches. • PW is seeking sponsorship of the project from WDFW under RCW 77.55.181. PW sent a letter to WDFW in September (2019) requesting sponsorship of its project connecting Lick Creek to the Teanaway River (EXHIBIT 2). BACKGROUND: In 2017, PW negotiated a revised contract for Teanaway Hydraulic Improvements with the Federal Highway Administration (FHWA) at the request of WDFW. Specifically, the Department requested replacement of the culverts at Lick Creek with a fish passage structure. PW took delivery of the project in late 2017. In early 2018, PW presented a preliminary design concept for agency consideration. Connecting Lick Creek across Department of Natural Resources (WADNR) property received support from the regional Yakima Tribal fish biologist and DNR land manager. Opposition from a County resident appears to have resulted in WDFW's stated concerns regarding connection of Lick Creek. Nearly ten months later and at a cost of an estimated $80,000, PW has now defined the adverse impact of keeping Lick Creek in roadside ditches following replacement of existing culverts with a fish passable bridge. Page 1 of 5 PUBLIC WORKS BOARD OF COUNTY CONSGSSIONERS WORK SESSION STAFF REPORT DISCUSSION: Adverse flooding impact to area residents is predicted by culvert replacement. Our initial hydraulic assessment assumes all roadside ditches remain open. Both the FHWA and area residents question our assumption of open culverts during a 100 year flood event. As a final flood assessment, PW has recently directed a final assessment assuming all culverts plugged and the bridge installed (EXHIBIT 3). Adverse impacts appear unavoidable keeping the creek in roadside ditching. FISCAL EMPACTS: Owing to the increased need for hydraulic and survey work, PW will likely exceed original cost share obligations delivering the project. Impacts to project costs are not available at this time. ATTACHMENTS: Exhibit 1: Flood rise analysis (08-28-2019) Exhibit 2: Letter and flood analysis sent to WDFW 09-20-2019 Exhibit 3: Flood rise analysis all culverts plugged Page 2 of 5 PUBLIC WORKS BOARD OF COUNTY CONMSSIONERS WORK SESSION STAFF REPORT EXHIBIT 1: FLOOD RISE AINALYSIS (08-28-2019) Page 3 of 5 PUBLIC WORKS BOARD OF COUNTY COMMISSIONERS WORK SESSION STAFF REPORT nhc N northwest hydraulic consultants NHC Ref. No. 2003112 28 August 2019 Kittitas County Public Works 411 N Ruby Street #1 Ellensburg, WA 98926 Attention: Mark Cook, P.E. Public Works Director Via email: Mark.cook@.co.kittitas.wa.us Re: North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Flood Rise Analysis - Maintaining Creek Flows Along Teanaway Road 1 INTRODUCTION PURPOSE: This technical memorandum summarizes the hydraulics assessment that was completed under the direction from Kittitas County Public Works to identify flood rise impacts resulting from maintaining creek flows along Teanaway Road; as part of the North Fork (NF) Teanaway Road, Lick Creek fish passage enhancement project. The Washington State Department of Fish and Wildlife (WDFW) has requested a flood rise analysis on the NF Teanaway Road, Lick Creek fish passage enhancement project, in order to consider granting Kittitas County protections afforded for fish barrier removal projects (RCW 77.55.181). Previously, Kittitas County has promoted reconnecting Lick Creek to the Teanaway River, which would eliminate flooding along the current alignment of Lick Creek downstream of the Teanaway Road crossing. This analysis provides the additional requested information to assist WDFW in assessing whether they will take actions to support the County's original proposed project and streamlined permitting through RCW 77.55.181. BACKGROUND: Kittitas County was awarded Federal Lands Access Program (FLAP) grant funds from FHWA to replace four culverts on Teanaway Road. WDFW approached the County to see if resources and funding could be transferred to address the Lick Creek barrier, which wasn't part of this original funding package. Lick Creek is a top -priority watershed for WDFW, DNR, USFS, and Yakama Nation for salmon recovery. The County coordinated with FHWA to transfer funding and added Lick Creek as a priority, understanding the importance of the culvert replacement. Since that time, collaborative efforts have continued throughout the Lick Creek watershed, including habitat enhancement and bridge replacement projects. This flood analysis included three main tasks: site reconnaissance, hydrologic analysis, and hydraulic analysis; these are discussed in the following sections. The project site is located in Kittitas County, WA, along the NF Teanaway Road, which crosses Lick Creek approximately 17 miles from Cie Elum. Upstream of the project location, Lick Creek flows predominantly from the northwest to southeast. Near the project site, Lick Creek turns to follow a north to south orientation before it discharges into the North Fork Teanaway River, approximately 2,000 feet further downstream (Figure 1-1). The existing crossing at the North Fork Teanaway Road consists of two culverts, a 54 -inch diameter reinforced concrete pipe, and a corrugated metal pipe with a 36 -inch inlet diameter and a 48 -inch outlet diameter. The project proposes to replace these existing culverts with a minimum 40 -foot span bridge located approximately 175 feet north of the existing crossing, which will meet Washington State Department of Fish and Wildlife (WDFW) criteria and will allow for natural stream processes. The proposed structure will follow design guidelines for hydraulics based on criteria from the United States Federal Highway Administration (FHWA), Washington State Department of Transportation (WSDOT) and WDFW. In addition to the new structure, Lick Creek will be realigned to its previous, more natural alignment, which removes the near 90 degree bends and locations where Lick Creek flows along the roadway embankment (Figure 1-1). North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Flood Rise Analysis — Maintaining Creek Flows Along Teanaway Road nhc 2 SITE RECONNAISANCE NHC visited the project site on March 29, 2018 with Jacobs and Kittitas County personnel to discuss potential alternatives and gather pertinent information to support the basis of design. An additional site visit was conducted on April 12, 2019 with Kittitas County personnel to assess additional survey needs and meet with property owners to gain insight to their experiences with flooding along Lick Creek. The existing crossing consists of two culverts, a 54 -inch diameter reinforced concrete pipe culvert and a corrugated metal pipe culvert with a 36 -inch diameter inlet and a 48 -inch diameter outlet. Some woody material was observed racked near the inlets of the culverts (Figure 2-1). Streambed material in the vicinity of the culverts, as well as in the adjacent upstream reach, was primarily sand. Figure 2-1 Inlets of Culverts at Lick Creek Crossing (Left) and View of Upstream Reach from Roadway (Right) Immediately downstream of the NF Teanaway Road crossing, the channel is wider (Figure 2-2, left) than the typical downstream channel section (Figure 2-2, right). This change in width is likely due to the velocities exiting the existing culverts. Downstream from this location, the creek has been channelized and is significantly less sinuous than the observed sinuosity upstream of the crossing. Through this straightened portion of the downstream reach of Lick Creek, there are several private properties with driveway culverts and structures within the floodplain of Lick Creek. North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Flood Rise Analysis — Maintaining Creek Flows Along Teanaway Road 4 Figure 2-2 Downstream View from the Existing Crossing of Lick Creek at North Fork Teanaway Road (Left) and Typical View of the Downstream Reach of Lick Creels (Right) During the April 12, 2019 site visit, culverts that influence the flow of Lick Creek were assessed and flagged to be included in the topographic survey to be collected by the Kittitas County survey crew (Figure 2-3). Below is a list with a brief summary of each culvert that is shown in Figure 2-3. Culvert 1— 6 -foot diameter, Corrugated Metal Pipe (CMP) located below a private property driveway. Culvert 2 —11 -foot wide, 6 -foot tall CMP arch located below a private property driveway. Culvert 3 — 8 -foot diameter, CMP located below a private property driveway. Culvert 4 North —4.5 -foot Reinforced Concrete Pipe (RCP) located below NF Teanaway Road. Culvert 4 South — 3 -foot CMP (actual culvert is a 3 -foot CMP inlet, 4 -foot CMP outlet) located below NF Teanaway Road. Culvert 5 —18 -inch diameter, CMP located below a private driveway. Culvert 6 — 24 -inch diameter, CMP located below a private driveway. Culvert 7 —15 -inch diameter, CMP located below a private driveway. Culvert 8 —18 -inch diameter, CMP conveying NF Teanaway Road ditch flow to Lick Creek Culvert 9 —15 -inch diameter, CMP located below a private driveway. This culvert was excluded from the hydraulic model per discussions with Kittitas County. Culvert 10 —15 -inch diameter, Corrugated Polyethylene (PE) Pipe located below a private driveway. Culvert 11 -15 -inch diameter, Corrugated Polyethylene (PE) Pipe located below a private driveway. Culvert 12 —12 -inch diameter, CMP located below a private driveway. North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Flood Rise Analysis — Maintaining Creek Flows Along Teanaway Road Figure 2-3 Culverts in Model Domain North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Flood Rise Analysis — Maintaining Creek Flows Along Teanaway Road nhc 3 HYDROLOGIC ANALYSIS 3.1 Watershed Analysis The project is located approximately 2,000 feet upstream of its confluence with the NF Teanaway River, which is located approximately 1.5 river miles upstream of the confluence between the main and north forks of the Teanaway River (Figure 1-1). Lick Creek conveys flow and sediment from an approximate 6.1 square mile basin situated on the south and southeast of the Teanaway Butte between the North and Middle Forks of the Teanaway River (Figure 3-1). Basin elevations are 2,270-, 2,310-, and 4,460 -feet (NAVD88) near its confluence with the NF Teanaway, at the project site, and at the peak of the watershed, respectively. The mean annual precipitation in the Lick Creek drainage basin is 42.2 inches. Approximately 53% of the basin has a canopy cover that consists primarily of Ponderosa Pine (at lower elevations) and Interior Douglass Fir vegetation zones (USGS 2018). These vegetation zones are impacted by recurrent fires, where recent fires have burned a significant portion of the Lick Creek Basin (WSDNR, 2018). Over 50% of the total watershed area was burned in the 2017 Jolly Mountain Fire and about 10% had been previously burned in the 2005 Lick Creek Fire. Impacts from the recurrent fires and the dense network of forest roads in the watershed and has potential to increase runoff, landslide frequency and sediment yield. North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project 7 Flood Rise Analysis — Maintaining Creek Flows Along Teanaway Road nhc Figure 3-1 Topographic Overview of the Lick Creek Basin North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Flood Rise Analysis — Maintaining Creek Flows Along Teanaway Road 3.2 Peak Flow Analysis There are no published or current streamflow gages on Lick Creek, or a nearby similar watershed, which could be used for determining peak streamflow values at the project site. Therefore, the USGS Regional Regression equations were utilized to determine peak flows. The USGS Region 2 Regression equations (Mastin et al., 2016) yielded peak flow estimates using basin characteristics determined by StreamStats (USGS, 2018). The estimated peak flows, with the flows used in the preliminary hydraulic analysis shown in bold, along with the standard error of prediction are summarized in Table 3-1. It should be noted that there is large uncertainty in the hydrology, as shown by the standard errors of prediction in Table 3-1. However, without a basin hydrologic model or available stream gage, it provides the best available information to be used in the hydraulic modeling. A sensitivity analysis on hydrology can be conducted as the project proceeds through design, however the flows provided in Table 3-1 were utilized to provide a preliminary assessment of hydraulic conditions (Section 4) for both existing and proposed conditions through the modeled reach. Table 3-1 Peak Flows for Lick Creek at the North Fork Teanaway Road Crossing Mean Recurrence Interva? (MRI) USGS Region P Regression Equation USGS Region 2 Regression Equation Standard Error of 2 -Year #cfs} 70 �redf[tior� ��6J 77.2 50 -Year 230 .. tt270 :0 120 4 HYDRAULIC ASSESSMENT The preliminary hydraulic assessment of the existing and proposed Lick Creek crossings were performed using SRH -2D (U.S. Bureau of Reclamation, 2016), a two-dimensional, depth -averaged hydraulic model. The SRH -2D model allowed for a detailed understanding of the hydraulics through the model domain. 4.1 SRH -21) Model Development 4.1.1 Model Domain and Terrain Data The project channel and floodplain geometry data for the SRH -21) model were obtained from topographic surreys collected by Kittitas County personnel and delivered to NHC in an AutoCAD format. The terrain data for the existing conditions model is based on the survey data collected by Kittitas County in late spring of 2019, after the snow had melted near the project site. The terrain data for the North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Flood Rise Analysis — Maintaining Creek Flows Along Teanaway Road 9 proposed conditions model is based on design surfaces (40 -foot hydraulic openings) that was provided by Jacobs to N HC in XML format. The topographic surfaces were imported into the Surface -water Modeling System (SMS) (Aquaveo, 2019). SMS is a computer program which provides a user interface for building and running hydraulic models, including SRH -21D. Utilizing the topographic surfaces, meshes were created for both existing and proposed conditions. A mesh is the computational domain of the hydraulic model and is utilized by SRH - 2D to calculate water depth, velocity, and other hydraulic parameters. The hydraulic model domain extends approximately 2,030 feet downstream and about 1,070 feet upstream of the existing NF Teanaway Road crossing. 4.1.2 Boundary Conditions The downstream boundary condition location was placed sufficiently far enough away from areas of interest to not influence the hydraulic results. The downstream boundary condition consists of water surface elevations that correspond to the mean recurrence interval of the peak flow being modeled. A sensitivity analysis on the downstream boundary condition was performed to obtain an accurate representation of the water surface profile (e.g. no rapid drawdown) and to determine if changes affected hydraulics through the areas of interest. To determine potential effects from flooding of the NF of the Teanaway River, FEMA water surface elevations for various floods on the NF of the Teanaway River were utilized to assess how they effect flooding of Lick Creek. Based on a sensitivity analysis of various water surface elevations at the confluence of Lick Creek and the NF of the Teanaway River, it was determined that FEMA flood elevations on the NF Teanaway River do not effect flood inundation limits or conveyance of the most downstream private property culvert (culvert 3 in Figure 2-3) or conditions upstream of this location. The upstream boundary condition defines inflow (see Section 3.2 for determination of peak flow estimates). The upstream boundary condition was placed sufficiently far enough away from the project site to not influence the hydraulic results at the NF Teanaway Road crossing. The inflow for all peak flow simulations was designated subcritical to match the expected flow regimes on Lick Creek at the boundary condition. The model was run in steady-state mode for all modeled simulations. Boundary conditions were also specified at the surveyed inlet and outlet of the existing culverts (Figure 2-3). This enabled SMS to interact with the Federal Highway Administration (FHWA) HY-8 culvert analysis software (FHWA, 2016) for calculating the hydraulics through the existing culverts. Geometric culvert data based on the Kittitas County survey were incorporated into the model. Based on direction from Kittitas County, the culverts for both existing and proposed conditions were assumed to be unobstructed from debris and ice. Therefore, the modeling of obstructions on existing culverts is beyond the scope of this analysis. It is important to note that as the project progresses, a risk-based approach can be completed using the hydraulic model as a tool to assess varying hydrology, structure openings, and evidence of previous flooding experienced by property owners. Once an existing North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project 10 Flood Rise Analysis — Maintaining Creek Flows Along Teanaway Road nhc conditions model best replicates the flood inundation that is experienced by the property owners, the hydraulic model can then be used to compare this baseline condition to the proposed project condition. 4.2 Model Results The following sections provide a summary of the flood rise analysis hydraulic results for the existing and proposed conditions along Lick Creek. The County requested water surface elevations during the 2- and 100 -year flow to allow WDFW to assess potential impacts due to the project. The 2- and 100 -year USGS regression equation peak flows are provided in Appendix A. All results are in the NAVD88 datum. 4.2.1 2 -Year Flow Figures A-1 and A-2 in Appendix A provide water surface elevations during the estimated 2 -year peak flow (70 cfs) for the existing and proposed conditions, respectively. Figure A-3 provides a comparison of water surface elevations between the proposed and existing conditions to show how the proposed project may effect water surface elevations along Lick Creek. In general, there is minimal to no change in water surface elevations outside of the County right of way, through the private properties, as shown by the white color in Figure A-3. There is a reduction in water surface elevations upstream of the existing NF Teanaway Road culverts due to their removal as well as the additional conveyance provided by the proposed 40 -foot bridge. Immediately downstream, and through the realigned portion (approximately 325 feet downstream of the proposed crossing) of Lick Creek, there is an increase in water surface elevations (shown as red in Figure A-3) due to the proposed alignment currently being dry in the existing conditions. This area, based on historic aerial photos, is one of the historic alignments of Lick Creek. 4.2.2 100 -Year Flow Figures A-4 and A-5 in Appendix A provide water surface elevations during the estimated 100 -year peak flow (270 cfs) for the existing and proposed conditions, respectively. Figure A-6 provides a comparison of water surface elevations between the proposed and existing conditions to show how the proposed project may effect water surface elevations along Lick Creek. During existing conditions (Figure A-4 in Appendix A), the two NF Teanaway Road culverts do not have sufficient capacity to pass the estimated 100 -year peak flow without having backwater. This backwater, located upstream of the culverts, results in the forest service road on the southwest bank of Lick Creek to overtop (Figure 4-1). The 2D hydraulic model estimates approximately 44 cfs overtopping the forest service road, with the remainder of flow being conveyed through the two existing NF Teanaway Road culverts. As the flow overtops the forest service road, it follows a ditch along the west side of NF Teanaway Road, crossing several private driveways and overtops the NF Teanaway Road in two locations (Figure A-4). For modeling purposes, the model domain ended just south of culvert 9 in Figure 2-3 as the topography south of this area increases in elevation, thus directing the water to the north and overtopping the NF Teanaway Road back into Lick Creek. These locations of overtopping were confirmed based on discussions with Kittitas County staff, property owners, and evidence of erosion on the east side of the NF Teanaway Road embankment during the April 12th, 2019 site visit (Figure 4-2). North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Flood Rise Analysis — Maintaining Creek Flows Along Teanaway Road Q1T Figure 4-1 lick Creek Looking Upstream over NF Teanaway Road Culverts and Forest Service Road Figure 4-2 Location Along East Side of NF Teanaway Road Showing Evidence of Previous Overtopping North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project 12 Flood Rise Analysis — Maintaining Creek Flows Along Teanaway Road nhc During the modeled proposed conditions (Figure A-5 in Appendix A), the backwater (due to the existing two NF Teanaway Road culverts) is eliminated and thus no overtopping of the forest service road occurs. This is due to the increased conveyance from the proposed 40 -foot bridge, which will meet WDFW water crossing design guidelines to allow for natural stream processes and unimpeded fish passage. While the proposed design restores the natural drainage path of Lick Creek, it increases the flow ("'44 cfs during the estimated USGS 100 -year flow and unobstructed culverts) downstream compared to existing conditions due to flow no longer overtopping the forest service road and flowing down the west NF Teanaway Road ditch. This increase in flow has some effect on the water surface elevations through the private properties. The highest increase in water surface elevation is approximately 0.4 feet nearthe inlets of the private property culverts. This suggests that the private driveway culverts may have not been designed to convey the 100 -year flow without overtopping, which is not uncommon for low volume roads or privately owned crossings. It is unlikely that any of the culverts in the model domain were designed based on the attenuation that upstream culverts may have, as engineering standard practice is to design water crossings for steady-state, peak flow conditions. With this said, the preliminary hydraulic model results provide graphics as a way to continue discussions with the property owners and to discuss potential changes to Lick Creek due to restoring the natural drainage path, stream processes and unimpeded fish passage through the NF Teanaway Road crossing. Figure A-6 in Appendix A shows a reduction in water surface elevations upstream of the existing NF Teanaway Road culverts due to the additional conveyance provided by the proposed 40 -foot bridge. Similar to the 2 -year results, immediately downstream and through the realigned portion (approximately 325 feet downstream of the proposed crossing) of Lick Creek, there is an increase in water surface elevations (shown as red in Figure A-6) due to the proposed alignment currently being dry in the existing conditions. This area, based on historic aerial photos, is one of the historic alignments of Lick Creek. The other red areas throughout Lick Creek are also representative of locations where the 100 -year estimated flow did not inundate (was dry) during existing conditions. As mentioned above, the highest increases in water surface elevations (approximately 0.4 feet) compared to existing conditions are near the private driveways, likely due to the culverts not being designed to convey the 100 -year flow without backwater. In general there is no increase in water surface elevations downstream of culvert 3 (shown in Figure 2-3). This is due to all of the flow in existing conditions being in Lick Creek, as the flow in the west NF Teanaway Road ditch overtops and re-enters Lick Creek upstream of this location. 5 CONCLUSION This technical memorandum summarizes the hydraulics assessment that was completed to assist WDFW in assessing whether they will take actions to support the County's original proposed project to afford protections and streamlined permitting for fish barrier removal projects through RCW 77.55.181, The hydraulic model developed, as part of this flood rise analysis, is a tool which can be utilized to assess changes in hydraulic characteristics due to changes in hydrology or assumptions of existing or proposed infrastructure. This assessment provides the requested information from WDFW, allowing discussions with stakeholders to assess project goals and communicate potential changes due to the NF Teanaway Road fish enhancement project. North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Flood Rise Analysis — Maintaining Creek Flows Along Teanaway Road 13 6 REFERENCES Aquaveo (2019). Surface -water Modeling System v13.0.9. Federal Highway Administration (2016). HY-8 Culvert Hydraulic Analysis Program, Washington D.C. Available at: https://www.fhwa.dot.goy/engineering/hydrauIics/`software/hv8/. Mastin, Mark C., Christopher P. Konrad, Andrea G. Veilleux, and Alison E. Tecca (2016). Magnitude, Frequency, and Trends of Floods at Gaged and Ungaged Sites in Washington, Based on Data through Water Year 2014: Scientific Investigations Report 2016-51.18. United States Geological Survey. Reston, VA. United States Bureau of Reclamation (2016). Sedimentation and River Hydraulics — Two Dimensional (SRH -2D) Model v3. United States Geological Survey (2018). "StreamStats in Washington." ,/� httl)s*//streamstats.usjzs.gov/ss/ (August 2018). Washington State Department of Natural Resources (2018). Fire Prevention & Fuel Management Mapping System, Washington Large Fires 1973-2018 Data. Available at: ,'� https://fmanfire.dnr.wa.eov/default.asnx (August 2018). DISCLAIMER This document has been prepared by Northwest Hydraulic Consultants, Inc. in accordance with generally accepted engineering practices and is intended for the exclusive use and benefit of Kittitas County and their authorized representatives for specific application to the NF Teanaway River in Kittitas County WA. The contents of this document are not to be relied upon or used, in whole or in part, by or for the benefit of others without specific written authorization from Northwest Hydraulic Consultants, Inc. No other warranty, expressed or implied, is made. Northwest Hydraulic Consultants, Inc. and its officers, directors, employees, and agents assume no responsibility for the reliance upon this document or any of its contents by any parties other than Kittitas County. Sincerely, Northwest Hydraulic Consultants Inc. North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project 14 Flood Rise Analysis — Maintaining Creek Flows Along Teanaway Road nhc APPENDIX A North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project 15 Flood Rise Analysis — Maintaining Creek Flows Along Teanaway Road Figure A-1 Existing Conditions Water Surface Elevation (WSE), USGS Regression 2 -Year Flow (70 cfs) North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Figure A-2 Proposed Conditions Water Surface Elevation (WSE), USGS Regression 2 -Year Flow (70 cis) North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Figure A-3 Water Surface Elevation (WSE) Comparison, USGS Regression 2 -Year Flow (70 cis) — Change in Water Surface Due to Proposed Project (Warm Colors = Increase in WSE, Cool Colors = Decrease in WSE Compared to Existing Conditions) North Fork Teanaway Road -Lick Creek Fish Passage Enhancement Project Figure A-4 Existing Conditions Water Surface Elevation (WSE), USGS Regression 100 -Year Flow (270 cfs) North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Figure A-5 Proposed Conditions Water Surface Elevation (WSE), USGS Regression 100 -Year Flow (270 cfs) North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Figure A -B Water Surface Elevation (WSE) Comparison, USGS Regression 100 -Year Flow (270 ds) — Change in Water Surface Due to Proposed Project (Warm Colors = Increase in WSE, Cool Colors = Decrease in WSE Compared to Existing Conditions) North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project EXHIBIT 2: LETTER AND FLOOD ANALYSIS SENT TO WDFW 09-20-2019 Page 4 of 5 PUBLIC WORKS BOARD OF COUNTY CONMUSSIONERS WORK SESSION STAFF REPORT September 20, 2019 DEPARTMENT OF PUBLIC WORKS Mark Cook, Director Mike Livingston, Regional Director WDFW South Central Rion 1701 South 24th Avenue Yakima, WA 98902-5720 RE: WDFW Support of Lick Creek Culvert Replacement Project The goat of our respective agencies has been working together for meauingfai improvements to fish passage and aquatic habitat when opportunities arise. Most recently, the County received Federal Highway Adminiatrahon funding assistance through their FLAP Grant program to replace fish passage barriers on Tearaway Road. To provide brief history, your agency requested the County consider reassigpiing the funding allocation to replace the Lick Creek fish passage barrier, which wasn't part of this original funding package. Lick Creek is a top -priority watershed for WDFW, DNR, USFS, and Yakama Nation for salmon recovery. In partacrship with WDFW, the County coordinated with FHWA to transfer funding and added Lick Creek as a priority replacement, the importance of the wished. Since that time, collaborative efforts have continued throughout the Lick Creek and Tearaway watersheds, including habitat enhancement and bridge replacememt projects Kittitas County has promoted reconnecting Lick Creek to the NF Teanaway River across DNR property, which would eliminate flood risk on the current alignment and damage to public and private iufiastructure, restore natural stream processes, and allow for a more resilient stream based on Mely future conditions. This is our preferred project. The enclosed informatiion provides the analysis requested by your agency regarding potential effects to charnel migration in the NF Teanaway River and the potential increase in flood risk if the creek were left in the new charnel. With this submittal, we believe you have all information required to determine if you will sponsor the project as a Fish Habitat Enhancement Project as outlined in RCW 77.55.181. Without this support, the project is at risk of not moving forward to construction. We have a meeting with Scott Downes of your staff October 3, 2019 at 9:00 am in Ellensburg. Please let me know how the Department will notice us of your decision sponsoring the re- connection of Lick Creck to the Tearaway River and the associated decision timeline, The requested additional analysis has significantly reduced our federal pemth% turnaround time supporting a 2020 construction bid solicitation. Sincerely, Mark R Cook Public Works Director Encl: Lick Crock Hydraulic Design Decision lMemo (NF Teanaway River Cmomorphic Analysis; Lick Creek Flood Rise Analysis) Cc w:/enol: Scott Downes, WDFW Scott NicolaL Yakama Nation William Meyer, WDFW Page 2 of 2 Lick Creek Hydraulic Design Decislor: Memorandum 32 North 3rd Street 3 tte 32D Yeldma, WA 9=1 Subject: Lick Creek Hydraulic Design Decision Memorandum,- Teanaway Road Hydraulic Impravements Attention: Mark Cook, Kittitas County Director Public Works From: Jacobs Project Manager Date: September 8, 2019 Introduction and History Kittitas County Public Works received Federal highway Administration (FFIWA) funding through their FLAP Grant program to replace fish passage barriers on Teanaway Road. In 2016, Washington Department of Fish and Wildlife (WDFW) requested the County consider reassigning the funding allocation to replace the Lick Creek fish passage barrier, which wasn't part of this origlnal funding package. Lick Creek Is a top -priority watershed for WDFW, DNR, USFS, and Yakama Nation for salmon recovery. In partnership with WDFW, the County coordinated with FHWA to transfer funding and added Lick Creek as a priority replacement, understanding the importance of the watershed. Since that time, collaborative efforts have continued throughout the Lick Creek watershed, including habitat enhancement and bridge replacement projects. The Lick Creek Fish Passage Enhancement Project includes replacing two total barrier culverts under North Fork Teanaway Road, Including a 54 -Inch diameter reinforced concrete pipe, and a corrugated metal pipe with a 36 -inch Inlet diameter and a 494nch outlet diameter. The project will replace these culverts with a 40 -foot span bridge located approximately 175 feet north of the existing crossing on the natural Lick Creek alignment meeting FHWA and WDFW hydraulic design criteria and restoring natural stream processes. Downstream of NF Teanaway Road, Lick Creek is highly altered from historic flow paths. This Includes an approximate 1,000 -foot length that has been straightened where it flows through private driveways. The creek in this section is entrained between NF Teanaway Road and private properties preventing natural hydraulic processes to occur. in addition, during higher flows the existing culverts under NF Teanaway Road cannot convey flood capacity, causing the Forest Service Road to the south to overtop and send water south down the NF Teanaway Road Ditch. This water then overlaps NF Teanaway Road, causing repeated damage to the roadway. Flood waters that stay in the existing Lick Creek channel also leave the channel and cause damage to private properties. ; Memorandum Due to these concerns, FKWA and the County, in coordination with WDFW, the Yakama Nation, and Department of Natural Resources (DNR), investigated re-routing Lick Creek across DNR property. This alternative would eliminate flood risk and damage to public and private infrastructure, restore natural stream processes, and allow for a more resilient stream based on likely future conditions. This is the County's preferred project alternative. Summary of Methods and Analysis Completed When the re-routing of Lick Creek across DNR property was presented to the downstream property owners as the preferred route to eliminate their flood risk, they expressed concern that additional flows Into the North Fork Teanaway River at this location would cause bank erosion and property damage. To inform this risk, the County used their own funding and delayed project design until an analysis could be completed. The County also requested a sub -surface geotechnical analysis be completed at this same time to ensure suitable soil conditions and lack of obstructions on the new stream alignment. s+ibsu*= Geow-hakat invesu adw —The County excavated three test pits at varying locations on the proposed stream alignment, each to the depth of just below the proposed new channel elevation. Aspect Consulting geotechnical engineers oversaw the work, analyzing soil conditions. No obstructions were found, and soil conditions are suitable for channel realignment. NF Tewwwway River Geomwphk Analysts— In order to address the concerns of property owners, the County requested Northwest Hydraulic Consultants (NHC) conduct an analysis of the potential change in channel migration rates of the NF Teenaway River as a result moving the Lick Creek channel (Attachment 1). This was not a comprehensive Investigation of geomorphic conditions or processes occurring In the subject reach but defined the potential sensitivity of the rarer to this small change in hydrology. The results of this assessment showed a minor potential increase in channel migration rates may occur from movingthe confluence of Lick Creek upstream. However, the increase is minor compared to the baseline condition which Is a very active channel within a large channel migration zone (CMZ). Any potential channel migration as a result of moving Lick Creek would most likely Influence areas within the existing CMZ where substantial exposure to channel migration risks are already present. Any additional migration would mostly Influence areas already exposed to channel migration hazards that are near the channel or within the meander belt. The potential for the added flow to increase the rate of channel erosion into terraces surrounding the floodplain is most likely to be a very small fraction of the increase In predicted lateral channel migration rates. In addition, the analysis Indicated the channel cross section width is not expected to substantially change. Liar Crie-0 Fhmd Rise Anafp& —The property owners did not agree with the results of the channel migration memo and were not willing to support the project. At that time, the County decided to refine the existing FHWA data and flood rise modeling to more accurately Inform the risks to properties by leaving Lick Creek in the existing channel (Attachment #). This was again at County expense and delayed the project for a year. However, in due diligence, the County wanted a refined model to share with property owners and WDFW to validate the risks and inform the projiect. WDFW requested the Memorandum Information so they could better understand risks and continue the partnership with the County by sponsoring the project as a Fish Habitat project. The refined hydraulic model showed the Increase in flow from removing the NF Teanaway Road culverts as an obstruction has some effect on the water surface elevations through the private properties. The highest Increase in water surface elevation Is approximately 0.4 feet near the inlets of the private property culverts. This suggests that the private driveway culverts may have not been designed to convey the 100 -year flow without overtopping. The model also assumed all private crossings were operating at full capacity. Any blockages to these culverts would presumably raise the water surface elevations above those modeled. Design Decision The County and project team are continuing with the design of the new Lids Creek channel across DNR property as the preferred alternative. This is based on the Information In the attached documents and the points below: • Replacing the LJrck Creek culverts with a 40 -foot bridge on NP Teanaway Road, and leaving the creek in its existing channel, would result in increased flood risk to private properties. This risk would be exacerbated if the private crossings were blocked during a high-flow event. Property owners have Indicated their main concern Is to stop the continued flooding from Lick Creek. The new channel across DNR eliminates this flood hazard and risk. • Lick Creek is currently highly -channelized and constrained between NFTeanaway Road and private residences with little natural hydrologic function. A new lick Creek channel across DNR property would provide enhanced functions like sediment and debris movement, fish passage (eliminates passage need on three private crossings), fish and aquatic habitat, and restore natural channel dynamics and hydrologic function. • Leaving Lick Creek In the existing channel would require long -tern maintenance and management through the private properties. The new bridge and channel will be designed to provide natural channel functions and eliminate the need for on-going channel maintenance. The fish passage and habitat enhancement elements provided by the new channel continue the investment In the Teanaway River Basin by cooperative partners and agencies, Including WDFW, Kittitas County, DNR, US Forest Service, FHWA, National Marine Fisheries Service, and the Yakama Nation. JACOBS Attachment 1 Memorandum NF Teanaway River Geomorphic Analysis nbc NHC Fir. No. OOIOOQlu September 11, 2018 Kittitas County Public Works Department 411 N Ruby ST, Suite 1 Ellensburg, WA 98926 Attention: Mark Cook, F.E. Public Works Director Via emall: mark.cookgffico.kittitas.wa.us Re: Proposed fLIdk Creek Realignment Assessment of Potential Changes to Morphodynwrdc Processes in the Noah Fork of the Teansway River Draft Assessment INTRODUCTION Northwest Hydraulic Consultants, Inc. (NHC) has been requested to assist Witas County with the design of a new water crossing to convey Lick Creek under the North Fork (NF) Teanaway Road. One alternative for the new Lick Creek water crossing is to relocate the current crossing to the east, along with realigning the channel downstream of the NF Teanaway Road. This proposed new channel would joln the NF of the Teanaway Rimer, approximately 2,500 feet upstream of the current confluence location; Increasing flows In the reach between the current confluence location and the proposed confluence location. This change could lead to potential impacts to channel morphodynamics, Including channel morphology and migration rates. The purpose of this memo is to provide the results of a geomorphic analysis of the potential changes to channel migration rates or processes in the NF of the Teanaway Riverthat might result from changing the confluence location of Lids Creek. This is not a comprehensive Investigation of geomorphic conditions or processes occurring in the subject reach, but rather a focused evaluation of the potential sensitivity of the river to a small change In hydrology, The assessment was completed with limited available information on channel hydrology and hydraulics and was based on the substantial assumptions that were outlined in the scope of work for Modification Number 1 to Delivery Order Number 2 (dated May 23„ 203,8) for the Kittitas County Teanaway Road Hydraulic Improvements Project. Observations of the river and computations used to evaluate the magnitude of potential Impact are summarized in the following sections. This assessment will provide Klttltas County with additional Information to determine the feasibility of the project given other project constraints. NHC Is also yri�rr rrsouer sp#catlF nhc engaged In the technical investigations to help support the design of a new and relocated water crossing; as well as a realigned lick Creek channel, which will be delivered under a separate report. The project site is located In Kittitas County, WA along the NF of the Teanaway River, approximately 6 miles northeast of Cie Elum (Figure 1). At the project location, lick Creek exits a relatively narrow alluvial valley into the broader NF Teanaway River Valley. Downstream of the current NF Teanaway Road crossing location, Lick Creek has been straightened to flow into a narrow corridor between private homes and the NF Teanaway Road. Numerous private culverts cross the creek along this straightened reach. Due to historic flooding and sedimentation on private properties, a part of the proposed design to replace the existing culverts with a bridge includes realigning Lick Creek by excavating a new channel on public (DNR) land. Potential impact of Lick Creek relocation on the AFF Teanaway River Morphodynamics nhc APPROACH For any given river under typical conditions, channel migration rates are proportional to bed material transport rates (Wickert et al., 2013; Constantine et a], 2014; Nelson and BOO, 2016). A standard practice in fluvial geomorphology Includes the estimation of bediaad transport rates at the reach -scale from the volume of material exchanged due to channel migration (e.g. Neill, 2983; Ham and Church, 2000). Here we apply the inverse reasoning as an estimate of the potential Impact of a change in hydrology on channel migration rates. More specifically, we assume an estimate of a potential Impact on the lateral channel migration rate Is that it is proportional to the change in sediment transport capacity for the reach. This is a conservative assumption because some bed material is conveyed directly down the channel without exchange between the active river and floodplain that is expressed as bar growth and bank erosion. This means that sediment transport estimates from lateral channel migration will be minimum estimates. in the present Investigation, the Implication is that the channel migration rate Is proportional, to a power less than 1, to the bedload transport rate. Bedload transport rates can be estimated from channel geometry and discharge (hydraulics), as well as from bed material composition. Here we use these parameters to determine the relationship between the bedload transport rate and discharge so that changes in the transport capacity, due to Increased discharge In the reach between the current and proposed lick Creek confluence locations, can be estimated. Bedload transport rates that are estimated In this way are subject to substantial (order -of magnitude) uncertainty without collection of calibration data; but relative changes In transport capacity, due to changes In hydraulics, can be much better constrained. Due to the character of the reach (described in the following section), and the fact that the relationship between the bedload transport rate and the channel migration Is expected to be proportional to a power less than 1, this procedure inherently provides a conservative estimate of the maximum plausible Impact of the added flow. of the required input parameters, the hydrologic change Imposed by relocating lick Creek is the least well known. At the county's request, we have not conducted any model -based hydrologic or hydraulic Investigation to estimate this Impact. The hydrology was estimated by regression relations, which have very broad confidence bounds, while the hydraulics were estimated by a normal depth calculation, which does not account for backwater conditions. The channel character was evaluated by reviewing available L1DAR data, walking a portion of the subject reach, defining the bed material and bed material grainsixe distribution, and mapping: historical channel positions from available aerial photos. General understanding of the channel character gained from this analysis supports the applicability c fthe theoretical framework (outlined above) that served as the basis for a quantitative estimate of the potential Impact on lateral channel migration rates. In addition to evaluating the potential Impact on channel migration rates, we evaluated the expected Impact of the additional flow on the channel width by applying the change in flow to a rational regime model of the channel. This analysis is described in Section 4. Potential impact of Lick Creek relocation an the NF Tean away River Morphodynamics 4 nhc 3 REACH CHARACTER Field Observations The reach of the NF Teanaway, between the proposed realigned lick Creek confluence and the existing confluence (Figure 2), is dominated by a cobble -boulder bed material (Photo 1 through Photo 3) with local areas of scour to bedrock (Photo 2 and Photo 3), as well as transient deposits of pebble ravel and gravel (Photo 4). It has a plane -bed, long proflle morphology with areas of localized scour around large wood (Photo 5), bedrock exposure (Photo 2), and anabranch channel confluences. The river has an Irregular to meandering planform with localized flow splits around nobble bars and a few stable islands. Single -thread segments range in width from about 60 to 100 feet, with a typical width of about 85 feet. Some areas split around bars and are substantially wider (120 to 150 feet), bringing the average channel width to 90 feet. A random -walk Wolman (1954) pebble count (Figure 3) was collected from the head of a large island bar, approximately 375 feet upstream of the proposed Lick Creek confluence location (Figure 2 and Photo 1). This bar head corresponds to the first riffle crest upstream of the proposed confluence. The bar is somewhat bimodal, with small cobble to gravel deposited over a distinctly larger cobble armor layer. It is similar to typical bed conditions observed through the reach, but there is variability around this typical material (Photo 2 through Photo 4). Areas of substantially larger substrate (large cobble to small boulder) are locally present In the thalweg. Several patches of highly mobile pebble -gravel to medium gravel were also observed, but these have little overall Influence on the bed morphology and are interpreted to be transient deposits that were deposited during the falling limbs of the most recent flood(s). Potential impact of Lick Creek relocation on the NF Teanaway River Morphodynamics ti .0 Lim q, nhc 3 4 V Photo 1: Characteristic Cobble -Gravel Bed Material at the Location of the Pebble Count Used for Sediment Transport Calculations. Inset Show a Scaled Photo at the Bar Surface, the Largest Aperture in the Pictured Grawloynew Is 128mm to a Ede potential impact of Lick Creek relocation on the NF Teanaway River Morphodynamics 5 nhc Photo 2: Example of Anomalously Coarse Cobble Bed Materlal and Scour to Bedrock at the Edge of the Alkndal Valley Photo 3: Example of Characterlstk Cobb"rarel Bed Material and Scour to Bedrock In the Center of the Valley Potential impart of Lick Creek relocation on the Ni: Teanaway (fiver Morphodynarnics _ ,'� � ",.,;,:- fit �-1• � • �r. ,�.�•w!. Via•.' �y,�� .�'_ s 14, it Photo 4: temple ofTransfent POW"rwwi Deposit Phaco 5: Example of Scour Around Large Wood Potential Impact of Lick Greek relocation on the NFTeanaway River Morphodynamic5 9 nhc Photo f: Example of Typlml Sank Mu tdol, Fishllghting SimiRarities of Sank and Channel Substrates wdnw*o O=) 4 B 16 32 84 128 256 512 1024 I t 900 f4nfvN � CaGble 8iaelder • i 80 70 so 20 iD i n 2 3 4 5 6 7 8 6 10 awrMin a" Figure 3: Cumulative Grainsite Distribution for the KF Teanaway River Pebble Count Used in Sediment Transport Computation Puiential impact of Lick Creek relocation on the NF Teanaway River Morphodynarnics 10 nhc The banks are characteristically composed of coarse alluvial material with a simllar texture to that observed in the channel (Photo 6), with little overbank fines. Roots of Cottonwood and Ponderosa Pine were observed In some locations; these provide some limited bank cohesion which increases the bank's strength slightly and provides some resistance to channel widening and lateral channel migration. Systematic exposure of sandstone bedrock along the channel suggests that the depth of alluvial fill In the valley bottom Is similar to, or less than, typical channel scour depths. Bedrock formed grade -controlling sills are present in the bottom of scour features and wherever the channel abuts the valley wall. These bed and bank conditions suggest limited lateral channel mobility and that most bedload transport is conveyed down the channel without exchange of material between the channel and floodplain. A preliminary review of aerial photos, described in the following section, supports this Interpretation as the channel bar and scour patterns are highly dynamic, while the lateral position of the active channel has been quite stable. 3.2 Historic Channel Migration Channel positions were delineated from historic aerial photos from 1963,1984,1998, 2006, and 2017 to evaluate a baseline channel migration rate for the subject reach (Figure 4). individual time period, reach average bank erosion rates are very slow, ranging from 0.8 to 2.4 faet/year, with a'whole period average of 1.6 feetfyear. Individual actively migrating meanders moved somewhat faster, with a maximum observed long-term migration rate of about 5 feet/year. The above reported values are reach average channel migration rates, but there is substantial variability depending on local conditions along the channel. Bedrock exposures largely act as barriers to lateral channel migratlon, as can anthropogenic features or—at least temporarily— bank reinforcement from the roots of large trees or accumulations of large woody debris. Local lateral migration rates are shown for three of the most active meanders in the project area in Figure 4 and Include rates up to 5 feet year. The most upstream meander (Meander 1 In Figure 4) has slowly amplified and translated down -valley with a fairly consistent bank erosion rate of about 3 feet/year. A side channel is present on the left bank/south west valley wall opposite this meander. It first became apparent in the 1984 aerial photo, but It is not dear whether it formed between 1963 and 1984, or It possibly was not visible in the relatively poor quality 1963 aerial image. The middle meander (Meander 2) translated rapidly down - valley between 1963 and 2006 but stalled out around 2006. it appears to have amplified to the point that flow cuts across the Inside orf the meander bend in a chute cutoff, leaving the outside of the bend relatively Inactive for the time being. Detailed local investigation of bank conditions and river hydraulics would be required to better understand the likelihood of the outside of the meander reactivating. The downstream most meander (Meander 3) has been moving at a rate of about 1 foot(year. In some areas between active meanders—particularly where the channel is entrained against bedrock on the left valley wail—no measurable channel migration has occurred since 1963. Potential impact of lick Creek relocation on the NF Teanaway River Morphodynarnics 11 Rgure 4: Historic Acdwe Channel Margins Potential impart of lick Creek relocation ars the NrTeanaway River Morphodynamics 12 nhc The dominance of down -valley meander migration Illustrates how channel migration is expected to mostly occur In areas relatively close to the existing active channel. In particular, the meander beit— defined as the area within an envelope connecting the outside of meander bends—is the most vulnerable to future erosion (Olson at al., 2014). Furthermore, the dominance of down valley meander migration, as opposed to cross -valley meander amplification, results in a fairly narrow channel migration zone (CMZ) (Illustrated in Appendix A) compared to that which would be extrapolated from the average bank erosion rates computed for the river if most migration occurred In the cross -valley direction. BEDLOAD TRANSPORT RATING CURVE As described above, a bedload transport rating curve (Figure 5) was developed based on estimated channel hydraulics and bed material composition. This provides a conservative estimate of the maximum expected impact to channel migration caused by the Increased flow In the reach between the current and proposed lick Creek confluence. The Wilcock and Crowe (2003) bedload transport function, as implementaed in BAGS (Pitlick at al., 2009b, 2009a) sediment transport program, was utilized to do this. The channel cross-section was cut from Bathymetric, Green Band L OAR data (PSRC and Quantum Spatial, 2015) provided by the County, and a floodplaln roughness of Manning's n-0.05 was assumed, with values of 0.025 and 0.08 used to test sensldvity to the assumption. Channel roughness was estimated from the bed material grainsize distribution as a part of the BAGS hydraulic computations (as described by Pitlick et al., 2009a). The reach average long profile slope (0.008) was used as the input slope (rather than a hydraulic gradient) because a hydraulic model of the reach was outside the scope of this investigation. This bed slope is similar to the modeled 1"ar water surface slope (0.01) in the existing Flood Insurance Study (FEMA 2018) as it suggests that the use of the bed slope to characterize shear stress at typical channel4brming flows Is appropriate. The slope was determined as the average riffle -crest to riffle -crest reach slope. This was measured between the first riffle upstream of the cross- section location, utilized for sediment transport calculations, to a riffle crest near the existing confluence. Figure 5 shows variability (shown as dashed lines) in the estimated bedload transport rating curve due to changes in the floodplain roughness—which Impacts flow partitioning between the channel and floodplaln and flow depth in the channel. The calculations are also extremely sensitive to the assumed channel slope because the bedload transport rate is an exponential function of shear stress (which is a direct function of slope). however, the general shape of the bedload transport rating curve Is relatively Insensitive to these uncertainties, and so the proportional change in sediment transport, due to a change in flow, will be similar regardless of the specific input values chosen. Potential impact of Lick Creek relocation on the NF Teanaway River Morphodynamics 13 100 —� .j 10 i 1 0.1 J I 0.001 100 B I L IL i000 10000 Figure 5: Computed Relationship Between Flow and Bedload Transport Rate. The Solid Line Represents a Floodplain Roughness Value of n=0.05, While the Dashed Lines Indicaee Results using Values of rpo0.025 and nwO.08. HYDROLOGIC AND BANK EROSION IMPACT OF REALIGNMENT The expected hydrologic impact of realigning Lick Creek was quantified by applying USGS regional regression relations, per the County's request, Regressions were completed for three separate basins and are listed in Table 1. Because of the contribution of localized precipitation and offsets in the timing between peak flows on the mainstem and tributaries, flood peaks scale less than proportionally to the basin area. This is reflected In the regresslon relations, as the exponent on basin area is less than 1. Potential impact of Lick Creek relocation on the NF Teanawray River Morphodynarnics nhc Because of this effect, It Is not appropriate to simply sum up Lick Creek and the NF Teanaway flood flow calculations. Rather, the hydrologic impact of realigning Lick Creek was evaluated by comparing regression -predicted flows from a basin consisting of the catchment to the NF Teanaway River only, to flows predicted from a basin consisting of the combined catchment of Lick Creek and NF Teanaway River (Table 2). For example, when calculated separately, the predicted 2 -year flow for the Teanaway Is 849 cfs, and 63 cis for Lick Creek. These two flows, determined separately, sum up to 912 cis which is 26 cis more then the predicted value of 886 cis, when the basins of Lick Creek and the Teanaway River are combined. This difference reflects the offset in timing between peak flows on Lick Creels and the mainstem Teanaway River. The USGS regression equations have a large standard error, with an order -of - magnitude spread between the upper and lower bound 90% confidence Intervals, and result in different flows than the Effective Flood Insurance Study (FIS). They are believed, however, to provide a reasonable estimate for the ratio of flows between the two basins. Resulting changes in flow (increases from about 4% to about 5% between the 2- and 100 -yr floods) and an estimated bedload transport rate (increasing from between 17% and 25%) are shown in Table 2. These calculations provide an upper bound estimate of the potential increase in lateral channel migration rates, suggesting that any increase In channel migration and bank erosion rates, due to the Lick Greek realignment, are expected to be modest. As explained in the introduction, the estimated change In the bedioad transport rate provides a conservative estimate of the expected change in bank erosion and channel migration rate. The expected change in the migration rate Is substentlally less than the computed 17% to 25% increase in bedioad transport rate. Table 1: Basin Charactwistks Used to Estimate Flood Flows Basin Area (miz) 87.8 6.1 93.9 Annual Precipitation (in) 46.8 42.2 46.5 Canopy Cover % 54.6 52.7 54.5 Table 2: Chane In Hydrology (C6) and Estimated 8edload Transport Rate (q6) Due to the Change in the Lkk Creels Confluence Location 2 84$ 0.24 886 0.28 4.4 17 5 1,240 1.4 1,300 1.7 4.8 21 10 1,520 3.3 11590 3.9 4.6 19 25 1,880 7.6 1,970 9.1 4.8 20 5o 2,200 13 2,300 16 4.5 25 100 2,490 23 2,620 27 4.8 17 Potential impact of Lick Creels relocation on the NF Teanaway River Morphodynamics 15 nhc Applied to the baseline reach average lateral migration rate of 1.6 feet/year, which was calculated by comparing historic aerial photos (section 3.2), this suggests an increase in the lateral channel migration rate, due to the realignment of Lick Creek, would be about 0.3 feet/year or less. Over a 50 -year period, this equates to about a maximum of 14 feet of additional lateral channel movement compared to an expected baseline of about 80 feet. Due to the dominance of down valley meander migration (illustrated In Section 3.2) most erosion due to this process will be expected to occur within the river's meander belt. Erosion will occur on both banks of the river, depending on the meander alignment, and result in both gain and loss of land in the right bank floodplain. The primary effect of the increased channel migration rate from the addition of flow from Lick Creek would be expected to have a slightly faster cycling of channel occupation within the floodplain. However, the effect of this added flow on the possible expansion of the CMZ over an engineering timeframe (decades to centuries) Is likely to be much smaller. REGIME WIDTH CHANGE In addition to changes In channel migration rates, the impact from a small addition of flow on the regime width of the channel was also evaluated. This was done by applying the concept of Rational Regime Theory, as implemented In the University of British Columbia UBC Regime Model (UBCRM), developed by Millar et al. (2014). Rational Regime Theory provides a useful tool for examining the key factors controlling the channel planform and hydraulic geometry, as well as potential flexibility In the channel form due to natural variability or human -induced changes in water and sediment supply. It Is a robust, physically -based approach to predicting channel dimensions that has been validated against a large empirical dataset (Eaton et al., 2004; Eaton and Church, 2007; Eaton and Millar, 2017). The UBCRM is based on this approach and accounts for many more of the key controlling variables than traditional empirical regime equations, while the required input data is sufficiently limited to be readily applicable. The model utilizes the controlling variables specified below. The model was parameterized with the following inputs: • the same grainsize distribution depicted In Figure 3 (D,OF=72 mm D84=170 mm), • the estimated channel forming discharge for both current and realigned conditions (choice of value described later), • the reach average slope of 0.008, + the default program suggested value of T* = 0.2, • and bank strength (p), calibrated to reproduce the current channel width (as recommended by Eatorw Personas communication 2015). The 2 -rear flow was used as the channel forming discharge for the NF Teanoway River (Q,-849 ds). The calibrated g value was very low (1.01), which is consistent with the observed similarity of the bed and bank material. Bank strength (µ) Is quantitatively defined as the ratio of shear stress required to mobilize the bank material to that required to mobilize the bed material. The calibrated value of 1.01 produced a Potential impact of Erick Creek relocation on the NF Teanaway River Morphodynarnics nhG channel width of 80.6 feet. Increasing the channel forming discharge to 886 ds, to account for the lick Creek contribution, results in an estimated channel width of 83 feet, suggesting the channel may widen an the order of 2 feet, a 3% increase relative to the current condition. Two feet of widening is a central estimate of the potential response, but uncertainty In all elements of the parameterization creates a range of plausible channel forms. Application of typical uncertainty associated with all Input parameters dwarfs the impact of the very small predicted change in channel - forming discharge. Figure 6 shows the results of a Monte -Carlo analysis based on the existing condition, applying a 5% uncertainty to the discharge, 10% to the pso, 20% to the Da4, and 20% to p. In contrast, Figure 7 shows the results of a Monte -Carlo analysis based on the existing condition and applying only a 5% change in discharge. The small scatter of results In the latter case (range of widths from 79 to 84 feet) compared to the fomes (range of widths from 59 to 98 feet) shows how insensitive the prediction of river morphology Is to this small change (4.496) In the governing hydrology. Potential impact of Lick Creek relocation on the NF Tesnaway River Morphodynamicss 17 100 50 0. 11111 15 20 25 30 33 width jml 150 100 so 0 100 , 0 35 30 25 2Q 15 0.7 0.5 0.9 1 080th IMl 0 1 2 3 4 OX 0.8 1 Transp. Cap. [mWslx 10 9 Deplh IM) Figure 6: UBCRM Uncertainty Analysis based on the Existing Condition and Applying a 596 Range to the Discharge, and Uncertainty of 10% to the Dsa 20% to the Dift and 20% to µ 1ngloolool.00m TrIMMEMW Width pnj au 60 40 20 0 ' 0.72 0.73 0.74 0.75 Depth lml 30 25 20 0 200ttp0 I, 1.5 1.0 1.7 1.8 1.9 0.8 0.7 0.8 0.9 Tronsp. Cap. pn3/sk 1e Depot imi Rgune 7: UBCRM Uncertainty Analysis Based on the Existing Condition and Applying Only a 5% Range to the Discharge Potential impact of Eyck Creek relocation on the NF Teanaway River Morphodynamlcs nhc 7 CONCLUSION This assessment suggests that moving the confluence of Lick Creek upstream may have an impact on channel migration rates In the reach that will receive additional flow between the current and proposed confluence locations. The increase Is minor compared to the baseline conditions and would most likely Influence areas within the existing CMZ (Appendix A) where substantial exposure to channel migration risks are already present. The analysis Is based on a vary conservative estimate of the potential Increase In lateral channel migration rates of 17% over what appears to be a fairly stable baseline condition (average of 1.5 feet/year), based on the modeled change in bedload transport capacity for the 2 -year flow (Figure 5, Table 2). The maximum expected increase In reach average lateral migration rate would be about 0.3 feet/year. Over a 50 year period, this equates to an additional 14 feet of lateral channel movement compared to the baseline condition which would result in SD feet of channel migration over the same 5U -year period. Due to a dominance of down -valley meander translation, this additional migration will mostly influence areas already exposed to channel migration hazards that are near the channel or within the meander belt. The potential for the added flow to increase the rate of channel erosion Into terraces surrounding the floodplain cannot be quantified with available data but is most likely to be a very small fraction of the Increase in predicted lateral channel migration rates. In contrast, the channel cross section width is not expected to substantially change. Rational Regime model assessment suggests the expected widening Is on the order of 2 feet, or about a 3% Increase In the width. The magnitude of this impact Is dwarfed by along -channel variability In width, with areas as narrow as 60 feet and as wide as 15a feet, that results from localized variability in the principal controlling factors. While contributions of Lick Creek further upstream from the current discharge point is relatively minor, the existing baseline risk for the Teanaway River channel movement within the CMZ is currently substantial and has the potential to migrate within the CMZ. 4 Potential impact of Lick Creek relocation on the NF Teanaway River Morphodynarnics 19 nhc REFERENCES Constantine, J. A., Dunne, T., Ahmed, J., Legleiter, C., and Lazarus, E. D. (2014). Sediment supply as a driver of river meandering and Floodplain evolution in the Amazon Basin. Nature Geasdence, advance online publication. doi.10.1038/ngeo2282. [online] Available from: http://www.nature.com/ngeoAournal/vaop/ncurrent/fuiVngeo2282.h1ml?WT.mc id=TWT Nat ureGeosd (Accessed 10 November 2014). Eaton, B. C., and Church, M. (2007). Predicting downstream hydraulic geometry: A test of rational regime theory. Journal of Geophysical Research. Earth Surface, 112(F3), F03025. doi:10.1029/2006J F000734. Eaton, B. C., Church, M., and Millar, R. G. (2004). Rational regime model of alluvial channel morphology and response. Earth Surface Processes and LancMums, 29(4), 511-529. Eaton, B., and Millar, R. (2017). Predicting gravel bed river response to environmental change: the strengths and limitations of a regime -based approach: PREDICTING RIVER RESPONSE: A REGIME - BASED APPROACH. Earth Surface processes and Landfarms, 42(6),994-1008. dol:10.1W2/espA058. Ham, D. G., and Church, M. (2000). Bed -material transport estimated from channel morphodynamics: Chilliwack River, British Columbia. Earth Surface Processes and Landforms, 25(10),1123--1142. Millar, R., Eaton, B., and Church, M. (2014). UBC Regime Model. [online] Available from: http://Ibis.geog.ubc.ca/-beaton/UBC%20Regime%20Model.htm] (Accessed 19 March 2015). Neill, C. R. (1983). Bank erosion vs bedload transport in a gravel river. River Meandering, ASCE, pp. 204-- 211. 04^211. [online] Available from: http://Cedb.asce.org/cgi/WWWdlsplay.cg7i?8400979 (Accessed 4 September 2015). Nelson, A., and Dubd, K. (2016). Channel response to an extreme flood and sediment pulse in a mbwd bedrock and gravel -bed river. Earth Surface Processes and Landfarms, 41(2),178-195. dol :10.1002/esp.3843. Olson, P. L., Legg, N. T., Abbe, T. B., Reinhart, M. A., and Radloff, J. K. (2014). A Methadology for Dellneating Planning -Level Channel Migration Zones (14406-025). Washington Department of Ecology Shorelands and Environmental Assistance, Olympia, WA. [online] Available from: https //fortress wo4pv/ecy/publications/SummaryPages/1406025.htmi. Pitiick, J., Cul, Y., and Wilcock, P. R. (2009a). Manual for computing bed load transport using BAGS (Bedload Assessment for Gravel -bed Streams) Software. [online] Available from: http://www.fs.fed.us/rm/pubs/rmrs_g x223.pdf?orlgln=publication_detail (Accessed 7 April 2014). Pitlick, J., Wilcock, P., and Cul, Y. (2009b). BAGS: Bedload Assessment in Gravel -bedded Streams. United States Forest Service Stream Systems Technology Center. [onilne] Available from: http://www.stmarn.fs.fed.us/Publication$/bap.htmi. Potential impact of Lick Creek relocation on the NF Teanaway River Morphodynamirs 20 nhc PSRC, and Quantum Spatial (2015). Teanaway Streams Topobathymetric Ll DAR. 36. Wickert, A. D., Martin, J. M., Tal, M., Kim, W., Sheets, B., and Paola, C. (2013). River channel lateral mobility: metrics, time scales, and controls: RIVER CHANNEL LATERAL MOBILITY. Journal of Geophysical Research: Earth Surface, 318(2), 396-412. doi:10.1029/2012JF002386. Wilcock, P., and Crowe, J. (2003). Surface -based Transport Model for Mixed -Size Sediment. Joumal of Hywdmulic Engineering, 129(2), 120-128. dal -10.2061/(ASCE)0733-9429(2W3)129:2(120). Wolman, M. G. (1954). A method of sampling coarse river -bed materials. transactions of theAmerlaon Geophyslcal Union, 35(6), 951-956. DISCLAIMER This document has been prepared by Northwest Hydraulic Consultants, Inc. In accordance with generally accepted engineering practices and is intended for the exclusive use and benefit of Kkdtas County and their authorized representatives for specific application to the NF Teanaway River lin Kittitas County WA. The contents of this document are not to be relied upon or used, in whole or in part, by or for the benefit of others without specific written authorization from Northwest Hydraulic Consultants, Inc. No other warranty, expressed or Implied, is made. Northwest Hydraulic Consultants, Inc. and its officers, directors, employees, and agents assume no responsibility for the reliance upon this document or any of its contents by any parties other than Kittltas County. Sincerely, Northwest Hydraulic Consultants Inc. Andrew Nelson, L.G. Staff Geomorphologist Author Casey Kramer, P.E. Principal Reviewer Derek Ray, P.Geo. Principal Reviewer Potenitial impact of Lick Creek reiocatlon on the NF Teanaway River Morphodynamics 21 nhc Appendix AI.: Maps illustrating historic Channel Positions, Previously Delineated CMZ, and Property Boundaries. Potential impact of Lick Creek relocation on the NF Teanaway River Morphodynamics 22 1 {•j���^+aar�•�.l.I.IAMiIrAi.. ,�` }Y�p55y ^ +� w•rr•. 00 ..a fw. +r� \ \\ •runw.. lopf\i'h�?y C!" \ j � t • i• r� f \ • rim \ . ' �.,i•r� sir • � fir' .1; � ♦` , y44 EEO 7 MR i IYrrAY�. yai`v.r.� r� Olfr^t LINE Cltf6f 411LYEil1 @IAf1E1f11'f �m�ne aau srm _ wr WMAS COINff 9.. aaraarse raemeicrs an Am .1 � I •I � r ismaa o�eva -sir wsa Quad - Its vawa aws� - ave 111aaw0 ewe6 - IIW I I i I mo .. ww I I � I 1_ -Ls J . ! 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Public Works Director Via email: Mark.co0k9.co.kftft@A.wa.us Re: North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Flood Rise Analysis - Maintaining Creak Flows Along Teanaway Road INTRODUCTION PURPOSE: This technical memorandum summarizes the hydraulics assessment that was completed under the direction from Kittitas County Public Works to identify flood rise impacts resulting from maintaining creek flows along Teanaway Road; as part of the North Fork (NF) Teanaway Road, Lick Creek fish passage enhancement project. The Washington State Department of Fish and Wildlife (WDFW) has requested a flood rise analysis on the NF Teanaway Road, Lick Creek fish passage enhancement project, In order to consider granting 10ttitas County prcftctions afforded for fish barrier removal projects (RCW 77.55.181). Previously, Kittkas County has promoted reconnecting Lick Creek to the Teanaway River, which would eliminate flooding along the current alignment of Lick Creek downstream of the Teanaway Road crossing. This analysis provides the additional requested Information to assist WDFW in assessing whether they will take actions to support the County's original proposed project and streamlined permitting through RCW 7755.181.. BACKGROUND: Kktitas County was awarded Federal Lands Access Program (FLAP) grant funds from FHWA to replace four culverts on Teanaway Road. WDFW approached the County to see if resources and funding could be transferred to address the Lick Creek barrier, which wasn't part of this original funding package. Lids Creek is a top -priority watershed for WDFW, DNR, USFS, and Yokama Nation fear salmon recovery. The County coordinated with FHWA to transfer funding and added Lick Creek as a priority, understanding the Importance of the culvert replacement. Since that time, collaborative efforts have continued throughout the Lick Creek watershed, including habitat enhancement and bridge replacement projects. This flood analysis included three main tasks: site reconnaissance, hydrologic analysis, and hydraulic analysis; these are discussed in the fallowing sections. The project site Is located in Kitdtas County, WA, along the NF Teanaway Road, which crosses Lick Creek approstmately 17 miles from Cie Elum. Upstream of the project location, Lick Creek flows predominantly nhc from the northwest to southeast. Near the project site, lick Creek turns to follow a north to south orientation before it discharges into the North Fork TeanawayRiver, approximately 2,000 feet further downstream (Figure 1-1). The existing crossing at the North Fork Tea noway Road consists of two culverts, a 54 -inch diameter reinforced concrete pipe, and a corrugated metal pipe with a 364nch Inlet diameter and a 484nch outlet diameter. The project proposes to replace these existing culverts with a minimum 40 -foot span bridge located approximately 175 feet north of the existing crossing, which will meet Washington State Department of Fish and Wildlife (WDFW) criteria and will allow for natural stream processes. The proposed structure will follow design guidelines for hydraulics based on criteria from the United States Federal Highway Adminlstratlon (FHWA), Washington State Department of Transportation (WSDOT) and WDFW. In addition to the new structure, Lick Creek will be realigned to its previous, more natural alignment, which removes the near 90 degree bends and locations where Lick Creek flows along the roadway embankment (Figure 1-1). North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project 2 Flood Rise Analysis — Maintaining Creek Flows Along Teanaway Road I11.1i'7 SITE RECONNAISANCE NHC visited the project site on March 29, 2016 with Jacobs and Kittitas County personnel to discuss potential alternatives and gather pertinent information to .support the basis of design. An additional site visit was conducted on April 12, 2019 with Otltas County personnel to assess additional survey needs and meet with property owners to gain Insight to their experiences with flooding along Lick Creek. The existing crossing consists of two culverts, a 54 -inch diameter reinforced concrete pipe culvert and a corrugated metal pipe culvert with a 36 -inch diameter inlet and a 48 -inch diameter outlet. Some woody material was observed racked near the inlets of the culverts (Figure 2-1). Streembed material in the vicinity of the culverts, as well as in the adjacent upstream reach, was primarily sand. Flgure Z-1 Inlets of Culverts at lick Creek Crossing (leM and View of UpWaam Ready from Readway (RISht) Immediately downstream of the NF Teanaway Road crossing, the channel Is wider (Figure 2-2, left) than the typical downstream channel section (Figure 2 2, right). This change in width Is likely due to the velocities exiting the existing culverts. Downstream from this location, the creek has been channelized and Is significantly less sinuous than the observed sinuosity upstream of the crossing. Through this straightened portion of the downstream reach of Lick Creek there are several private properties with driveway culverts and structures within the floodplain of Lldk Creek. North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Flood Rise Analysis — Maintaining Creek Flows Along Teanaway Road nhc Figure 2-2 Downstream View frons the iodating C raeaing of lick Creek at North Fork Teanaway Road (Left) and Typical View of the Downstream Reach of Lick Creek (Right} During the April 12, 2019 site visit, culverts that Influence the flow of lick Creek were assessed and flagged to be included In the topographic survey to be collected by the Kittitas County survey craw (Figure 2-3). Below is a list with a brief summary of each culvert that is shown in Figure 2-3. Cuhmrt 1— [Moot diameter, Corrugated Metal Pipe (CMP) located below a private property driveway, Culvert 2 —11 -foot wide, Irfoot tall CMP arch located below a private property driveway. Culvert 3 — 9-fac t diameter, CMP located below a private property driveway. Culvert 4 North — 4.5 -foot Reinforced Concrete Pipe (RCP) located below NF Teanaway Road. Culvert 4 South — 3 -foot CMP (actual culvert is a 3 -foot CMP Inlet; 4 -foot CMP outlet) located below NF Teanaway Road. Culvert 3 —18 -Inch diameter, CMP located below a private driveway. Culvert 6 — 24 -Inch diameter, CMP looted below a private driveway. Culvert 7—154nch diameter, CMP located below a private driveway. Culvert 8 —18 -inch diameter, CMP conveying NF Teenaway Road ditch flow to Lick Creek Culvert 9—154nch diameter, CMP located below a private driveway. This culvert was excluded from the hydraulic model per discussions with Kittitas County. Culvert 1D -15 -inch diameter, Corrugated Polyethylene [PE) Pipe located below a private driveway. Culvert 11 -15 -Inch diameter, Corrugated Polyethylene (PE) Pipe located below a private driveway, Culvert 12—124nch diameter, CMP located below a private driveway. North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Flood Rise Analysis — Maintaining Creek Flows Along Teansway Road nhc Figure 2-3 Culverts In Model Danaln North Fork Tea naway Road - Lick Creek fish Passage Enhancemcnt Project Flood 116e Analysts — Maintaining Creek Flows Along Teanaway Road nhc 3 HYDROLOGIC ANALYSIS 3.1 Watershed AnaWs The project Is located appnmdmateiy 2,000 feet upstream of its confluence with the NF Teanaway River, which is located approximately 1.5 river miles upstream of the confluence between the main and north forks of the Teanaway River (Figure 1-1). Lick Creek conveys flow and sediment from an approximate 6.1 square mile basin situated on the south and southeast of the Teanaway Butte between the North and Middle Forks of the Teanaway River (Figure 3-1). Basin elevation; are 2,27D-, 2,310-, and 4,460 -feet (NAVD88) near Its confluence with the NF Teanaway, at the project site, and at the peak of the watershed, respectively. The mean annual precipitation In the Lick Creek drainage basin Is 42.2 Inches. Apprmdmately 53% of the basin has a canopy cover that consists primarily of Ponderosa Pine (at lower elevations) and Interior Douglass Fir vegetation zones (USGS 2018). These vegetation zones are Impacted by recurrent fires, where recent fires have burned a significant portion of the Lick Greek Basin (WSDNR, 2018). Over 50% of the total watershed area was burned In the 2017 Jolly Mountain Fire and about 109E had been previously burned In the 2005 Lick [geek Fire. Impacts from the recurrent fires and the dense network of forest roads In the watershed and has potential to Increase runoff, landslide frequency and sediment yield. North Fork Teanaway Road - lick Creek Flsh Passage Enhancement Project 7 Flood Rise Analysis — Maintaining Creek Flows Along T'eanaway Road �1 LM7A tOGRCE8.'a161s 7:a� LiGMR � NhA � Rgure 3-1 Topogmphic OrerAew of the Lick Creek Basin North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Flood Rise Analysis — Maintaining Creek Flaws Along Teanaway Road nhc 3.2 Peak Flour Analysis There are no published or current streamffow gages on Lick Creek, or a nearby similar watershed, which could be used for determining peak streamfiow values at the project site. Therefore, the IISGS Regional Regression equations were utilized to determine peak flows. The USGS Region 2 Regression equations (Mastin et al., 2016) yielded peak flow estimates using basin characteristics determined by StreamStats (USGS, 2018). The estimated peak flows, with the flows used in the preliminary hydraulic analysts shown In bold, along with the standard error of prediction are summarized In Table 3-1. It should be noted that there is large uncertainty In the hydrology, as shown by the standard errors of prediction in Table 3-1. However, without a basin hydrologic model or available stream gage, it provides the best available information to be used in the hydraulic modeling. A sensitivity analysis on hydrology can be conducted as the project proceeds through design, however the flows provided in Table 3-1 were utilized to provide a preliminary assessment cf hydraulic conditions (Section 4) for both existing and proposed conditions through the modeled reach. Table 3-1 Peak Rom for Lick Creek at the North Fork Teanaway Road Cnmkg 2 -Year 70 77.2 10 -Year 140 72.2 25 -Year 190 81.2 50 -Year 230 89.2 100 -Year 270 96.9 500 -Year 380 120 HYDRAULIC ASSESSMENT The preliminary hydraulic assessment of the existing and proposed Lick Creek crossings were performed using SRH -2D (U,S. Bureau of Reclamation, 2016), a two-dimensional, depth -averaged hydraulic model. The SRH -213 model allowed for a detailed understanding of the hydraulics through the modes domain. SRH -2D Model Development 4.1.1 Model Domain and Terrain Data The project channel and floodplain geometry data for the SRH -ZD model were obtained from topographic surveys collected by Kittitas County personnel and delivered to NHC in an AutoCAD format. The terrain data for the adsting conditions model is based on the survey data collected by Klttitas County in late spring of 2013, after the snow had melted near the project site. The terrain data for the North Fork Teanaway Road - tick Creek Fish Passage Enhancement Project Flood Rise Analysis — Maintaining Geek Flows Along Teanaway Road nhc proposed conditions model Is based on design surfaces (W -foot hydraulic openings) that was provided by Jacobs to NHC in XML format. The topographic surfaces were Imported into the Surface -water Modeling System (SMS) (Aquaveo, 2019). SMS is a computer program which provides a user interface for building and running hydraulic models, including SRH -2D. Utilizing the topographic surfaces, meshes were created for both existing and proposed conditions. A mesh is the computational domain of the hydraulic model and is utilized by SRH - 2D to calculate water depth, velocity, and other hydraulic parameters. The hydraulic model domain extends approximately 2,038 feet downstream and about 1,070 fleet upstream of the existing NF Teanaway Road crossing. 4.1.2 Boundary Conditions The downstream boundary condition location was placed sufficiently far enough away from areas of Interest to not influence the hydraulic results. The downstream boundary condition consists of water surface elevations that correspond to the mean recurrence interval of the peak flow being modeled. A sensitivity analysis on the downstream boundary condition was performed to obtain an accurate representation of the water surface profile (e.g. no rapid drawdown) and to determine if changes affected hydraulics through the areas of Interest. To determine potential effects from flooding of the NF of the Teanaway River, FEMA water surface elevations for various floods on the NF of the Teanaway Rlver were utilized to assess how they effect flooding of Lkk Creek. Based on a sensitivity analysis of various water surface elevations at the confluence of Lick Creek and the NF of the Teanaway River, it was determined that FEMA flood elevations an the NF Teanaway River do not effect flood inundation limits or conveyance of the most downstream private property culvert (culvert 3 in Figure 2-3) or conditions upstream of this location. The upstream boundary condition defines inflow (see Section 3.2 for determination of peak flow estimates). The upstream boundary condition was placed sufficiently far enough away from the project site to not influence the hydraulic results at the NF Teanaway Road crossing. The inflow for all peak flow simulations was designated subcdtical to match the expected flow regimes on Lick Creek at the boundary condition. The model was run in steady-state mode for all modeled simulations. Boundary conditions were also specified at the surveyed inlet and outlet of the existing culverts (Figure 2-3). This enabled SMS to interact with the Federal Highway Administration (FHWA) HY-8 culvert analysis software (FHWA, 2016) for calculating the hydraulics through the existing culverts. Geometric culvert data based on the Kittitas County survey were incorporated Into the model. Based on direction from K'ittitas County, the culverts for both existing and proposed oonditlons were assumed to be unobstructed from debris and ice. Therefore, the modeling of obstructions on existing culverts is beyond the scope of this analysis. It is important to note that as the project progresses, a risk-based approach can be completed using the hydraulic model as a tool to assess varying hydrology, structure openings, and evidence of previous flooding experienced by property owners. Once an existing North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Flood Rise Analysis — Maintaining Geek Flows Along Teanaway Road nhc conditions model best replicates the flood inundation that Is experienced by the property owners, the hydraulic model can then be used to compare this baseline condition to the proposed project condition. 4.2 Model Results The following sections provide a summary of the flood rise analysis hydraulic results for the existing and proposed conditions along lick Creek. The County requested water surface elevations during the 2- and 100 -year flow to allow WDFW to assess potential impacts due to the project The 2 and 100 -year USGS regression equation peak flows are provided In Appendix A. All results are In the NAVD88 datum. �..�., i -Year Flow Figures A-1 and A-2 in Appendix A provide water surface elevations during the estimated 2 -year peak flow (70 cis) for the existing and proposed conditions, respectively. Figure A-3 provides a comparison of water surface elevations between the proposed and existing conditions to show how the proposed Project may effect water surface elevations along Lick Creek. In general, there is minimal to no change In water surface elevations outside of the County right of way, through the private properties, as shown by the white color In Figure 1-3. There Is a reduction in water surface elevations upstream of the existing NF Teanaway Road culverts due to their removal as well as the additional conveyance provided by the proposed 40 -foot bridge. Immediately downstream, and through the realigned portion (approximately 325 feet downstream of the proposed crossing) of Lick Creels there is an Increase in water surface elevations (shown as red In Figure A-3) due to the proposed alignment currently being dry in the existing conditions. This area, based on historic aerial photos, Is one of the historic alignments of Lids Creek. 4.2.2 100 -Year Flow Figures A-4 and A-5 In Appendix A provide water surface elevations during the estimated 100 -year peak flow (270 cfs) for the existing and proposed conditions, respectively. Figure A-6 provides a comparison of water surface elevations between the proposed and existing conditions to show how the proposed project may effect water surface elevations along Lick Creek. During existing conditions (Figure A-4 In Appendix A), the two NF Teanaway Road culverts do not have sufficient capacity to pass the estimated 100-Vrear peak flow without having backwater. This backwater, located upstream of the culverts, results In the forest service road on the southwest bank of Lick Creek to overtop (Figure 4-1). The 2D hydraulic model estimates approximately 44 cis overtopping the forest service road, with the remainder of flow being conveyed through the two existing NF Teanaway Road culverts. As the flow overtops the forest service road, It follows a ditch along the west side of NF Tearaway Road, crossing several private driveways and overtops the NF Teanaway Road In two locations (Figure A-4). For modeling purposes, the model domain ended just south of culvert 9 in Figure 2-3 as the topography south of this area increases in elevation, thus directing the water to the north and overtopping the NF Teanaway Road back into Lick Creek, These locations of overtopping were confirmed based on discussions with Klttltas County staff, property owners, and evidence of erosion on the east side of the NF Teanaway Road embankment during the April 12th, 2019 site volt (Figure 4-2). North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project Flood Rise Analysis — Maintalning Creek Flows Along Teanaway Road FIgur4 A-] Lick Creek Loakke UpsIm2rn witrNFTewwAW Road Culverts and ForettSet* c■Road Figure 4-2 Location Along East Side of NF Teanaway Road Showing Evidence of Previous Overtopping North Fork Tearaway Road - Lick Creek fish Passage Entrancement Project 12 Flood Rise Analysis — Maintaining Creek Flows Along Teanaway Road During the modeled proposed conditions (Figure A-5 in Appendix A), the backwater (due to the existing two NF Teanaway Road culverts) Is eliminated and thus no overtopping of the forest service road occurs. This Is due to the increased conveyance from the proposed 40-faat bridge, which will meet WDFW water crossing design guidelines to allow for natural stream processes and unimpeded fish passage. While the proposed design restores the natural drainage path of Lick Creek, it Increases the flow (-" ds during the estimated USG5100-year flow and unobstructed culverts) downstream compared to existing conditions due to flow no longer overtopping the forest service road and flowing down the west NF Teanaway Road ditch. This increase In flow has some effect an the water surface elevations through the private properties. The highest Increase in water surface elevation Is approximately 0.4 The near the inlets of the private property culverts. This suggests that the private driveway culverts may have not been designed to convey the lm -year flow without overtopping, which Is not uncommon for low volume roads or privately owned crossings. It is unlikely that any of the culverts in the model domain were designed based an the attenuation that upstream culverts may have, as engineering standard practice is to design water crossings for steady-state, peak flow conditions. With this said, the preliminary hydraulic model results provide graphics as a way to continue discussions with the property owners and to discuss potential changes to Lick Creek due to restoring the natural drainage path, stream processes and unimpeded fish passage through the NF Teanaway Road crossing. Figure A-6 in Appendix A shows a reduction in water surface elevations upstream of the existing NF Teanaway Road culverts due to the additional conveyance provided by the proposed 40 -foot bridge. Similar to the 2 -year results, immediately downstream and through the realigned portion (approximately 325 feet downstream of the proposed crossing) of Lick Creek, there Is an Increase In water surface elevations (shown as red in Figure A-6) due to the proposed alignment currently being dry in the existing conditions. This area, based on historic aerial photos, Is one of the historic alignments of Lick Creek. The other red areas throughout tick Creek are also representative of locations where the 100 -year estimated flow did not Inundate (was dry) during existing conditions. As mentioned above, the highest increases In water surface elevations (approximately 0.4 feet) compared to existing conditions are near the private driveways, likely due to the culverts not being designed to conveythe 100 -year flow without backwater. In general there is no Increase in water surface elevations downstream of culvert 3 (shown In Figure 2 -3) - This is due to all of the flow in existing conditions being In. Lids Creek, as the flow In the west NF Teanaway Road ditch overtops and re-errters Lick Creek upstream of this location. CONCLUSION This technical memorandum summarizes the hydraulics assessment that was completed to assist WDFW In assessing whether they will take actions to support the County`s original proposed project to afford protections and streamlined permitting for fish barrier removal projects through RCW 77.55.182. The hydraulic model developed, as part of this flood rise analysis, is a tool which can be utilized to assess changes in hydraulic characteristics due to changes in hydrology or assumptions of existing or proposed infrastructure. This assessment provides the requested information from WDFW, allowing discussions with stakeholders to assess project goals and communicate potential changes due to the NF Teanaway Road fish enhancement project North Fork Teanaway toad - Lick Creek Fish Passage Enhancement Project Flood Rise Analysis — Maintaining Creeik Flows Along Teanaway Road nhc 6 REFERENCES Aquaveo (2019). Surface -water Modeling System v13.0.9. Federal Highway Administration (2016). HY-8 Culvert Hydraulic Analysis Program, Washington D.C. Available at: htt s: www.fhwa.dot. ov en ineerin dr uiics so are/ h i3 . Mastin, Mark C., Christopher P. Konrad, Andrea G. Veilleux, and Alison E. Tecca (2016). Magnitude, Frequency, and Trends of Floods at Gaged and unpaged Sites in Washington„ Based on Data through Water Year 2014: Scientific investigations Report 21316,5118. United States Geological Survey. Reston, VA. United States Bureau of Reclamation (2016). Sedimentation and River Hydraulics — Two Dimensional (SRH -2D) Model v3. United States Geological Survey (2018). "Streamstats In Washington." 'Tb ltiitps.//streamstats.usa5.eov/ss/ (August 2018). Washington State Department of Natural Resources (2018). Fire Prevention & Fuel Management Mapping System, Washington Large Flres 1973-2018 Data. Available at: •11 ,itt s; fmanfirg dnr.wa.aov defauit.asgx (August 2016). DISCLAIMER This document has been prepared by Northwest Hydraulic Consultants, Inc. In accordance with generally accepted engineering practices and Is Intended far the exclusive use and benefit of Kittitas County and their authorized representatives for specific application to the NF Teanaway lover in Kittitas County WA. The contents of this document are not to be relied upon or used, in whole or in part, by or for the benefit of others without specific written authorization from Northwest Hydraulic Consultants, Inc. No other warranty, expressed or implied, is made. Northwest Hydraulic Consultants, Inc. and Its officers, directors, employees, and agents assume no responsibility for the reliance upon this document or any of its contents by any parties other than Kittitas County. Sincerely, Northwest Hydraulic Consultants Inc. North Fork Teanaway Road - Lick Creek Fish Passage Enhancement Project 14 Flood Rise Analysis — Maintaining Creek Flows Along Teanaway Road nhc APPENDIX A North fork Teanaway Road - Lick Geek Fish Passage Enhancement Project is Flood Rise Analysis — Maintaining Creek Flows Along Teanaway Road 49P FlgmA4 E;Oft Cmdftlwa WaterSurhm Ebvalm CWWEj USGS RogreseW 2 -Year Flow (70 A) North Fork Teansway Road - Lick Creek FL -h Passage Enhancement Project L MOM A-2 Proposed Candbons Water &ubm Elevation (MM. USM RgVMWon 2 -yaw Row (?a ata) North Fork Teanaway iluad - Ock [reek Fish Pamp Enhancement pmjga Flow%143 WMwStr *= ElevWbn (WSE) Cagmrb=, USW Repression E-Yw Flow (lU ob) — ChoW In WaW 8ulf Due to Proposed PMJW (Warm COkn - lnaeeae In WSE, Cool Colon a Demeeee in WSE Compered In Eldeft CarMws) North Fork Teanaway Raw - lack Creek Fnsh Passage EnhancemeW Project FWUMA-4 El HiqCmdfimVVWwArh=eew8Nm MSELuSIN RWmlon100-YOWSkm(Z7ecb) keF*rkTeano" Ftopd- Lick Creek Fish Enhr__Pmled r,. I - , ' mull ' L - : pjj ' CL Rqum A41 PmpomW OandMom VVMw Burk= E6vaft (WSE), USGS Regnmian 100-Yow Fbw GM da) North Fork Teanaway Road - Lid Crook Fish Passage Enhancement Prajoct 4 1.4111f " a. f �, t ! Its! ' tinea IN 41 ' f' P+� Al �1 /.j' • :WHT•_ l kkm a y 4 OL . ti ., Nv If : SoI i red a flaring In IM BMW thnt om Inundated In pmpaaad conditns, but dry In existing oonditiom Sand blue coloring Indicates areasthat ere bmdated in existing aonditiont, butin dry pnopmed * # d Vol eandMlanL Alla ilk assumed to be unobstructed. Figura IIS Wader Suarlecs EkmtU s MSE) Cotnpariaon, UM ReWmaalon 100 -Year Flaw WO da) — C hMP In Winter Surblsce Due to Ptopoeed Pr%W (warm Calors a Inotaaate In WSE, Co01 Gulose - Ommm me In WSE Competed to BMno Conditm) North Fork Teanaway head - Uck Creep FM Passage Enhancement Ptojam EXHIBIT 3: FLOOD RISE ANALYSIS ALL CULVERTS PLUGGED Page 5 of 5 PUBLIC WORKS BOARD OF COUNTY CONMSSIONERS WORK SESSION STAFF REPORT m x N 7� f0 n b O 7 v CD a 0 M CD O CD a m A C CD y r -r fD Q A SD 7 D1 O C U) cQ N y b 7 O O fD Al O N v O P_ N V 4 mm c a 0 0 CL n 0 CL o' 0 O c� =r Ch n 0 0 9 CD y C CD y d 0 cn a 0 c G) a y Vl 7 i C) 0 J l T O' N V C n N In n 0 Q ch 0 CD 0 X (D +' O N CD C2 C7 CD L 7 R1 O 9 c w 1 Q 0 CD Q n O 3 Q O C n CD s O N O C, UP Value Pii m u w rU. c m os 0 a 0 co CD Q C) O 7 a N4 0 0 v CD � N "I lD y O - or b- " 4rD 0 n CD a fA @ X CD � C l N C rr N !Z 0 Ol cn 7 N4 -114 - CDS lD y 4rD fD lv n 0 a fA @ v C 3 Q C V1 0 Ol ■ -Value ou wffii � a o mn cc ao ro a O N CD C1 0 O 7 Ll c' a O s N CD Zi O 3 CD N CD c CD N N r CU C c cn X CD ca N O 7 J C) 0 e CD w 0 V O N