DA-15-00001 Palomino Fields Master File

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HOW TO PLANT WILLOWS AND COTTONWOODS FOR RIPARIAN RESTORATION J. Chris Hoag, Wetland Plant Ecologist, USDA-NRCS Plant Materials Center, Aberdeen, Idaho Introduction Many riparian areas in the West need rehabilitation. Natural climatic events and abuses in the past have cause the desFuction of vegetation and accelerated streambank and stream bottom erosion (Kauffman and Krueger 1984; Skovlin 1984; Platts 1981; Thomas and others 1979). Emphasis on water quality, aesthetics, wildlife, and fisheries has prompted interest in methods for revegetating eroding stream channels (Carlson 1992; Carlson et al. 1991). There is increased interest in rehabilitating riparian zones with willows and cottonwoods. The Interagency Riparian/Wetland Plant r Streambank erosion in a corral and feeding . complex on Medicine Lodge Creek near Development Project, USDA Natural Dubois, ID Resources Conservation Service (NRCS), ` Plant Materials Center (PMC), Aberdeen, Idaho and others are researching harvesting, storage, planting techniques and cultural practices for successful establishment of willows, cottonwoods and other riparian woody vegetation to better meet the needs of riparian rehabilitation. Guiding Principles of Stable Stream Channels Riparian vegetation is a critical part of any stream system. Riparian plants provide a huge web of roots that hold the soil together. They also provide significant roughness from their above ground biomass. Determining where to plant them is often one of the hardest decisions to make. Before starting to restore a stream channel, 3 principles need to be understood (Natural Channel Designs, 2006). They are: 1. Elevations should rise away from the central channel. T The central channel flow line must be the lowest point across the riparian area and the channel banks, floodplains, and terraces should slope upward continuously away from the channel. The banks'will be most stable if they can be stepped as they rise away from the channel. All flat areas should slope toward the river. If they are level or slope away from the river they will tend to divert overbank flows away from the main channel and could contribute to greater erosion. Banks on the outside of meanders are expected to rise more rapidly than those on the inside, but should still be stepped when possible. 2. Transitions should be gradual to reduce the potential for erosion. In order to minimize the risk of lateral bank erosion, water should flow smoothly through the stream corridor. While meander is a natural part of stream processes, tight turns can create excessive pressure to weak stream banks and increase erosion. Meanders should be gradual and within the dimensions 2 �,.