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The recommendat:ion for stabilizing 1:his area LlCludes the use of structural methods such as riprap, gabions, or other methods placed on a slope cut to a1: least 1 vertical on 2 horizontal. This protection should be provided from the riverbed to a level of about the lOO--year flood. The upper portion of t.he bank could be protected by biotechnical stabilization methods. Design aids were provided to the city of Delta under separate cover. It should be noted that along portions of the riverbank where vegetation is already established, the bank appears to be stable at the upper levels. The veget.ative stabilization will also blend in well with the estl:etic concept of this portion of Confluence Park. Uncompahgre River Upstream from Confluence: Concern was E,xpressed about the stability of the river channel between tl:e northerly end of the fish pond and the confluence with tl:.e Gunnison River. The river in this area is adjacent to thE' future wildlife area and nature .trail which would be located around it. Inspection of the channel bed indicated that: t,he river channel in this area has migrated in the pe.st:. One method to stabilize the channel <:luring low to moderate flow in t:his area is the use of submerged Cjrade control structureE:. These structures couid direct the flow over them ir. the direction desired, thereQY establishing a low flow channel directly downstream of tile structures. In addition, the upst:ream portion of the rivar would experience a reduction in velocity due to the backwatier effect of the structure. The function of these structures during high flows such as a 5(1- or 100-year event is untested. with careful constructi.on of the foundation into the bank, and careful keying of appropriate sized bouldars on the streambed, there i.s no reason why the structures could not withstand the effEcts of higher flows. Tlie scour hole which typically forms downstream of the structure could undermine the structure immEdiately above it unless ,an apron is engineered into the system to eliminate tHe scour hole. In addition, biotechnical bank stabilization in this area, especially the uSe of willow trees, could enhance the area habitat and provic.e channel meander protection during higher flows. The Colora.do Division of wildlife has constructed several grade stabilization structures on the Roaring Fork River and elsewhere, and their advice should be sought if this solution is selected. The grade stabilization structure is a 10vi capital cost but potent;ially high-maintenance solution. In addition, it must be recognized that flows upstream of the structure will be elevated, with additional inundation consequences. Other methods to stabilize the channel in this reach include riprap bank protection and the placement of jetties. Riprap protection is a relatively expensive but reliable solution which may not be warranted for what is being 26