PUB00118

• Year: 2000
• Title: Arkansas River Water Needs Assessment
• CWCB Section: Interstate & Federal
• Author: Smith and Hill
• Description: Information and findings associated with the Arkansas River Water Needs Assessment study
• Publications - Doc Type: Historical

Arkansas River Water Needs Assessment - Section 1. Executive Summary

well 1982-1994 flows supported those values.
Table 1-2 provides daily flow values for this period
so that a typical flow can be determined for any
given day during the July 24-September 7 period.

The fact that the historic hydro graph is not neutral
in relationship to natural resource values is demon-
strated by examining specific flows. For example,
in a dry year during the 1982-1994 period, flows
recede to 700 cfs on about July 21. A 700 cfs flow
represents a significant departure from the
preferred flows of 350 cfs for juvenile trout.
Similarly, in a dty year during the 1982 to 1994
period, flows reach 500 cfs on about August 12.
This flow is significantly below the 1,500 cfs
optimum preferred by rafters on the river.

Turquoise Reservoir, Twin Lakes, and Clear Creek
Reservoir Water level Preferences

Various resource values have similar water level needs
at both Turquoise and Twin Lakes Reservoirs. All

TABLE 1-2

resources are benefitted by maintaining full reservoirs
as much of the time as possible, and with as little
water level fluctuation as possible. However,
resource managers recognize that reservoir operations
must continue in order to make water deliveries to
water users. With this in mind, resource values are
best supported when the reservoirs are kept as full as
possible during May, when the vegetation growing
season begins and when water temperatures become
warm enough to support significant biological
activity among fish populations.

Once the resetvoirs are full at the end of spring
runoff (typically around July 15), resource values
are best supported if reservoirs are not drawn down
by more than 10 feet between the fill date and
October 1. Drawdowns of more than 10 feer
reduce the primary productivity (basic food
production) of the reservoirs, and reduce the area
of feeding habitat for fish. In addition,
drawdowns of more than 10 feet affect the scenic
quality of the lakes for recreation use, and can
make some boat ramps unusable. Gradual drafting

Arkansas River at Wellsville Gage
Actual Measured Data (cfs), Representative Wet, Dry, and Average Years
Date Wet Year Dry Year Avg Year DateWet Year Dry Year Avg Year
Actual Actual Actual Actual Actual Actual
Jut 24 2,580 566 1.380 Aug 16 1.505 390 865
25 2,373 586 1,323 17 1.455 395 866
26 2,263 629 1.286 18 1.360 415 852
27 2,lBB 590 2,309 19 1,305 436 B35
28 2,173 550 1.189 20 1,395 390 B05
29 2,178 505 1,216 21 1,335 375 B20
30 2,070 459 1,203 22 1,300 377 825
31 2.01B 466 1,166 23 1.340 380 84B
Aug 1 2.330 426 1.120 24 1.361 368 B86
2 2,130 424 1,069 25 1,395 418 B89
3 2,005 451 1.049 26 1.431 415 853
4 1,930 516 1.050 27 1,370 413 822
5 1.915 525 1.003 28 1.344 407 789
6 2.075 454 1.002 29 1.2B3 394 753
7 2.145 491 1,025 30 1.200 364 722
8 2.000 478 979 31 1.164 343 693
9 1.860 %4 942 5ep 1 1.096 323 675
10 1.655 434 B86 2 1.059 309 645
11 1.5B5 434 B59 3 1,053 303 627
12 1,675 447 B68 4 1.032 315 611
13 1.685 440 871 5 9B9 329 596
14 1.695 430 B80 6 829 309 561
15 1,560 412 B69 7 BOl 299 552

Note: The representative wet year incorporates flows during 1983. 1984. 1985. and 1995. The representative dry year incorporates flows
during 1988. 1991, 1992, and 1994. The representative average year incorporates flows during 1982-1994.

Water Needed to Protect or Promote Critical Resource Values - 1-17