HOT SPRINGS — Depending on rainfall, Entergy Arkansas Inc. says it will allow lakes Hamilton and Catherine to refill early from the wintertime drawdown because of drought conditions in the Ouachita River watershed.
The lakes were originally scheduled to refill starting March 5. Entergy said in a news release that it will allow rainfall to help refill the lakes before the official refill date but urged property owners to be flexible.
Bobby Pharr, process superintendent of Entergy’s Hydro Operations, said the lakes should reach normal springtime levels by March 12.
“We hope the public understands the need for Entergy to do whatever possible to conserve water to allow Lake Ouachita to refill to its normal springtime level,” Pharrsaid in the release.
“We’re asking folks to be flexible during this critical time because the recent snows have begun to refill Lake Ouachita and we just don’t know how much rainfall will occur or how much the lakes will rise before the official refill start date.”
Entergy said lakefront property owners and lake users on lakes Hamilton and Catherine should take precautions if the area receives rainfall and the lakes begin to rise before the official refill start date.
Precautions include moving construction debris or leaf piles in the lakebed to higher ground, installing posts early for newly permitted facilities, or securing boats or floating docks properly to withstand higher water.
The company implemented its Drought Contingency Plan in January, which allows a reduction in its requiredcontinuous minimum flow from Remmel Dam, which forms Lake Catherine above the Ouachita River.
Article 404 of the Federal Energy Regulatory Commission Project 271 License requires Entergy to operate Lake Catherine within an elevation range of 304.0 to 304.5 feet mean sea level from March 1 - or when Lake Catherine is refilled from the annual drawdown, whichever is later - through May 15, to enhance spring fish spawning habitat.
Exceptions include drought conditions, emergency conditions, anticipatory drawdowns for storm events and actual or anticipated high inflow events.
Entergy said it will terminate its Drought Contingency flow reductions when Lake Ouachita rises above 570 feet above mean sea level. On Saturday, Ouachita was at 569.24feet msl, having risen 0.02 feet during the preceding 24 hours.
“Entergy will complete the refill of the lakes through rainfall inflows and generation from Blakely Mountain Dam, if needed, beginning March 5,” Pharr said.
Last November, Lake Hamilton was drawn down 3 feet and Lake Catherine was drawn down 5 feet as part of the annual wintertime drawdown.
Entergy, citing the National Oceanographic and Atmospheric Administration’s Palmer Drought Index, noted that the region was in a “moderate drought” condition beginning in October 2010 and intensified to a “severe drought” in January.
“Rainfall for the Ouachita River watershed is 10-20 inches below normal,” the release said.
Management of the three lake levels, through three dams, is part of a balancing act between Entergy and the U.S. Army Corps of Engineers, which manages Lake Ouachita and Blakely Mountain Dam.
“During the summer, Lake Ouachita’s level slowly falls through hydroelectric generation” at Blakely Mountain Dam. “This water is then passed through lakes Hamilton and Catherine and used again for hydroelectric generation at Entergy’s Carpenter and Remmel dams. Lake Ouachita then is allowed to refill during the winter months through rainfall,” the release said.
However, Entergy began restricting generation in October 2010 except for emergency electrical system demands and to maintain its required minimum flow into the Ouachita River below Remmel Dam. Entergy said it also generated to maintain levels on Hamilton and Catherine during the few rains experienced this winter.
Permits must be obtained from Entergy for any construction activity on the lake or shoreline, including boat docks, piers, walkways, swim docks, PWC ramps, decks, landings, embankments, bulkheads, seawalls, and dredging and filling operations. Relocation, replacement, enlargement or significant alteration of existing facilities also requires a new permit from Entergy.
Northwest Arkansas, Pages 7 on 02/22/2011