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This agreed upon requirement for berming raised questions among the Wildlife Commission, CDOW administrators, and the public about the potential cost of constructing berms along/around floodplain ponds. I contacted Bill Elmblad (CDOW) and requested that he seek cost estimate for these potential construction costs. He obtained a cursory estimate from a local gravel/construction company that formed the basis for cost estimates for constructing and reinforcing berms with rip-rap (Appendix D). To expand these cost estimates, costs were summarized and described as follows: Cost to build dike one foot high, 15 feet wide on top, and 1,000 feet long ............... $ 9,000 Cost to rip-rap dike one foot high on just the outside face at a thickness of 1.5 feet ........ $ 4,800 For any dike of additional height, multiply above costs by each additional one foot increment, e.g.: -- 3 foot high dike, ............ ......................................... $27,000 -- rip-rapped its entire length .............................................. $14,400 --total ................................................................ $41,400 It appears from Ehtnblad's example using Corn Lake (Appendix E), which was based on the review by CWCB (1995), that the entire pond perimeter would not have to be rip-rapped; only those portions of the dike affected by flowing water require rip-rap. CWCB (1995) provides suggested specifications for dike slopes and dimensions, but I am uncertain how these compare to FEMA standards. Corn Lake is approximately 10 surface acres. I used an estimated shoreline development factor of 1.2 to calculate a shoreline length of 2,907 feet. From the CWCB report it is estimated that to protect Corn Lake for up to a 50 yr flood would require a 2,800 foot long levee system averaging four feet in height (it would still be 15 feet wide on top). Based on the flowing water criterion, Elmblad estimated that a 1,000 foot segment of the dike would have to be rip-rapped to prevent erosion. Based on this information, it would cost an estimated $100,800 to install the dike and $19,200 to protect a segment of the dike from flowing water for an estimated total cost of $120,000. Note that these cost estimates do not include installation of a screen to control fish escapement. Using estimated shoreline development factors for the eight floodplain ponds for which CDOW prepared LMPs (Elmblad et al. 1994), I calculated an estimated total cost to construct berms for these public waters (Table 7). I took this exercise one step further by estimating the potential cost to construct berms for the privately owned pond resource within the 50 year floodplain of the Grand valley from the town of Palisade downstream to Loma. By categorizing ponds based on surface area, < 1 acre, 1-10 acres, 10-20 acres and ponds over 20 acres, and using an overall estimate of 1.5 for shoreline development, I calculated a weighted mean shoreline length for each category of ponds and used this value multiplied by the number of ponds in each size category to estimate total shoreline length. Again, berm costs were based on an average height of 4 feet, with 1/2 of the berm length being rip-rapped to prevent erosion (Table 8). Although this exercise provides a "what-if' glimpse of potential cost of berming ponds, berm construction and rip-rap in the floodplain is generally strongly discouraged (T. Ireland, U.S. Fish and Wildlife Service, personal communication). 16