freshare.net
The Arkansas Game and Fish Commission and the U.S. Army Corps of Engineers recently formalized a historic agreement on minimum flows from Norfork Lake into the tailwaters. The project calls for a steady release of cold water flowing from Norfork Dam that will benefit downstream trout when no hydropower is being generated.
The agreement details responsibilities between the AGFC and the Corps to prepare Norfork Dam and certain lakeshore recreation facilities so minimum flows can be implemented. On June 18, the Corps awarded a $6.7 million contract to Mobley Contractors Inc. of Morrilton, to make alterations at the dam that are necessary to enable the steady release of cold water.
Alterations are needed because at the time the dam and powerhouse were built, they were designed to make large hydropower releases, not the much smaller releases needed for minimum flows. Much of the funding, $3.67 million, was provided by the American Recovery and Reinvestment Act of 2009. The remainder is from Corps funds. This work is scheduled to be completed by December 2011.
On hand for the ceremony were Rep. John Boozman and Rep. Marion Berry, along with officials from the AGFC and the Corps of Engineers. Once the steps in the partnership agreement are completed, the Corps will start capturing water in Norfork Lake so minimum flows can begin.
Work under the contract entails constructing a remote controlled “siphon system” that will utilize 24-inch steel pipe to draw water from various depths in the lake as needed, siphon the water through the dam and release it downstream.
AGFC, the non-federal sponsor, will provide modifications of Corps lake facilities to allow for continued use of those facilities when the lake’s conservation pool level is raised 1.75 feet from elevation 552 feet to elevation 553.75 feet (555.75 feet during summer seasonal pool) to provide water storage for the minimum flows. The facilities include three boat ramps, seven swim beaches and two parking lots. This work will begin in September and be completed by February 2011. The estimated cost is $465,000.
The White River minimum flow issue is an old one, dating back nearly half a century when trout were stocked in the White River below Bull Shoals Dam and the North Fork River below Norfork Dam as a replacement for the native warmwater fishery wiped out by the dam’s cold-water release system.
The dams of the White River system were built for flood control and power generation. Ensuing years have brought a recreational trout fishing industry to Arkansas that has grown to international renown, bringing with it millions of dollars to the Arkansas economy.
When water flows are nonexistent, multiple problems arise - low food production (chiefly aquatic insects), habitat destruction, difficult small boat navigation and increased water temperatures. When there is no generation or flood release, only water that leaks through the dam reaches the river. The agreement will bring the trout fishery an adequate minimum flow for temperature control, food production and angler access.
While the physical effects on anglers fishing the rivers won’t be dramatic, adequate minimum flow will have a much more dramatic effect on a trout fishery already considered among the best in the world.