|
<br />.
<br />
<br />.
<br />
<br />beginning of spring
<br />through July releases
<br />of filling Yellowtail
<br />
<br />run-off based on a normal run-off forecast, March
<br />will be based on forecasted inflows with the objective
<br />Reservoir to elevation 3640 by the end of July,
<br />
<br />d, Others, Replacement storage up to a combined total of
<br />1,075,500 acre-feet can be made available in Clark Canyon, Tiber, and Canyon
<br />Ferry Reservoirs on a forecast basis, Fresno Reservoir in Montana is lowered
<br />each year and regulated to provided flood control in accordance with a June 4,
<br />1957, Letter of Understanding, In addition to the reservoirs covered in this
<br />report, other Bureau reservoirs, without allocated flood control storage
<br />space, will provide flood control in their normal operation of storing
<br />seasonal run-off, Some of these projects are Gibson Dam in Montana and Bull
<br />Lake, Pathfinder, Seminoe, and Buffalo Bill Dams in Wyoming,
<br />
<br />VII, MAJOR REGUIATION PROBLEMS. Regulation problems experienced during the
<br />period of this report are discussed briefly in the following paragraphs,
<br />
<br />A, Water Oualitv. Water quality problems including algal blooms and
<br />low dissolved oxygen exist at certain tributary reservoirs, The principal
<br />water quality issues and problems at each of the projects during 1989 are
<br />listed in Table 6,
<br />
<br />B, Downstream Channel Caoacitv, Inadequate or reduced channel capacity
<br />is a problem below many of the tributary reservoirs, Encroachment by natural
<br />plant growth due to low flows, by flood deposits left in place, and by human
<br />construction and agriculture practices are common. In some cases, downstream
<br />channel capacity Is significantly less than flood control releases, For
<br />example, the channel downstream of Cold Brook Dam is undefinable due to
<br />residential construction, The channel capacity of the South Platte River
<br />below the Tri-Lakes projects hinders or prevents releases in accordance with
<br />the three-reservoir (Chatfield, Bear Creek, and Cherry Creek) plan of
<br />regulation to evacuate flood storage, Compounding this situation is the fact
<br />that the reservoir design routings for Chatfield, Bear Creek and Cherry Creek
<br />Reservoirs were made independently of each other and that the individual
<br />routings neglected l) the effect of the releases from the other two dams in
<br />the three-reservoir system, 2) the effect of the incremental run-off below the
<br />dams, and 3) the actual channel capacity below the three dams,
<br />
<br />'"
<br />OJ
<br />..l
<br />'"
<br /><
<br />...
<br />
<br />C, Releases for Purooses other than Authorized Project Functions,
<br />Inquiries and requests received from states, cities, and other organizations
<br />for the release of water from the various projects for other than authorized
<br />purposes such as irrigation, water supply, and improvement of water quality,
<br />These requests pertain to supplemental discharges from the conservation pool
<br />or the retention of water and slow down of releases from the flood storage
<br />zone.
<br />
<br />D, Potential Hazardous Conditions, A potential problem exists if water
<br />is released over the project spillways where the land below the spillway has
<br />not been acquired and urban areas now exist, A hazard-to-1ife condition
<br />exists if a significant flow of water is discharged over the spillways at
<br />Cherry Creek Dam and Kelly Road Dam in Denver, Colorado; Salt Creek #17,
<br />
<br />14
<br />
<br />......
<br />
|