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recreation opportunity lost since the reservoir was drained and offsetting actual or perceived losses of sport fishing opportunity in riverine habitats. Flood lain Pond Resource Flooding Potential. and Berming Concerns Several key, discussions occurred during the negotiation of the draft Procedures pertained specifically to concerns about maintenance or development of non-salmonid sport fisheries within the 100-year floodplain (Critical Habitat) and the construction of berms around or along ponds adjacent to the river. Among these concerns was a perception by members of the water development and environmental communities that the floodplain corridors, especially along the Colorado River within the Grand Valley could become a channelized, rip-rapped river which would preclude flooded bottomland restoration for endangered fishes and would upset key nutrient dynamics between flooded habitat and the mainstem river. In response to these concerns about fish management within the floodplain, either for endangered or sport fishes, several comments and observations were quite relevant. First, most of the ponds in the floodplain were believed to lie within the 10 year floodplain, particularly along the Colorado River m the Grand Valley. Henry Maddux, USFWS, and I confirmed this belief upon examination of maps encompassing the river floodplains and surrounding lands along the Colorado and Gunnison rivers (Table 5). Indeed, the majority (55%) of the 246 ponds identified along the Colorado River within the Grand Valley appeared to lie in the 10-year floodplain. Another 22% of these ponds were within the 10-50 year floodplain thus totalling 771/o (72% of the total pond surface acreage) within the 50 year floodplain (Table 5). Another key point was, there is little vertical or horizontal variation within much of the floodplain between the 50-year and 100-year floodplains along the Colorado (CWCB 1995, FEMA 1992), Gunnison, White, or Yampa Rivers. This point was probably key in allowing a berm height up to the 50-year flood height to suffice for the purposes of the Procedures. Table 6 combines data found in FEMA (1992) and CWCB (1995) to illustrate the recent historic magnitude of flood events along the Colorado River within Critical Habitat. The most recent serious floods along the Colorado River occurred in 1983 and 1984 (FEMA 1992). Note that during the 1983 flood, all ponds shown in Table 6 were within the 10-year floodplain and would be expected to connect with the river during a similar event, i.e., fish could possibly enter or leave the pond depending on the depth of the connecting water flow. Also note that during 1984, the floodplain between Palisade and Fruita experienced a 40-year flood event, but the river flow in this reach nearly equaled but did not exceed the flow estimated for a 50-year event (Table 6). These data contributed to the rationale for constructing berms along/around ponds only up to the 50-year flood stage, per the Procedures. Exceeding the 50-year elevation functionally represents berm free-board which becomes an added cost in construction. As a result of the concerns about potentially excessive berming of the floodplain within Critical Habitat, a proposal was forwarded during negotiations surrounding the Procedures to cap the number and surface acres of ponds that could be diked and/or screened by CROW for developing/continuing management for nonnative warmwater fish species. The key issues were that berming ponds to accommodate management for warmwater sport fish would preclude a pond's use for grow-out of endangered fish and/or flooded bottomland restoration for benefit of endangered fishes. 13