Declining Trout Population
98.6% Drop In “Wild” Trout!
By Paul Honkavaara
In 1984 the estimated “wild” trout population in the Lower Kings River, the section from Pine Flat Dam to Highway 180, was 435 rainbow trout per mile. In 2015 that had dropped to 6 “wild” trout per mile. A drop of 98.6%!
From Kings River Conservation District (KRCD)
There are two primary reasons for that dramatic decline in the “wild” trout population.
One is the KRCD power plant that became operational in 1984. A US Fish and Wildlife Services (USFWS) report states:
“The position of the penstocks (el. 649.3) and low-level sluices (el. 565.5) were designed to be as low as possible in order to maximize the range of power generation and water yield, and water can only enter the penstocks through that one level. During spring and early summer power generation, the coldest water is used first, prematurely depleting the coldwater reserve in the lake, and resulting in warm water discharges later in the year that are lethal to trout.” (emphasis added)
The USFWS refers to those warm water temperature events that are lethal to trout “extinction episodes”. They occur in about 3 years out of 4 and kill all or almost all of the trout in both the reservoir and below Pine Flat Dam.
A second primary problem is the water flow through the Lower Kings River. A 1992 report from Trihey & Associates, the consultant to KRCD states:
“A second major factor limiting trout populations below Pine Flat Dam is the availability of living space and stream temperatures in the Kings River near the close and immediately following the close of the irrigation season. . . . Our analysis of physical habitat conditions indicates the best streanflows for adult rainbow trout within the 26.3 mile study area are between 200 and 400 cfs.”
By contrast the current minimum flow over Fresno Weir is 35 cfs. That is far less than the 200 to 400 cfs minimum flow recommended by the KRCD consultant.
To learn more about the issues of the Lower Kings River please go to:
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The Public Advisory Group (PAG) has been negotiating with the Kings River Fisheries Management Program (KRFMP) has been making significant improvements. One recent success was causing increased stocking in the Lower Kings River.
That stocking included the release of over 11,000 lbs of “trophy” (average 4 lbs) of rainbow trout into the Lower Kings River. Some club members caught their “personal best” rainbow trout.
PAG is continuing the negotiations with KRFMP. To address the two key issues of high water temperatures that cause the “extinction episodes” and inadequate flows PAG has requested that KRFMP agree to:
With those two changes it will be possible to re-establish a truly wild rainbow trout population in the Lower Kings River.
PAG has very extensive documentation available. Should you have any questions, would like additional information or would like to learn how you may become involved in PAG please contact Hank Urbach at email@example.com or Paul Honkavaara at firstname.lastname@example.org.