RAPID CITY, SD – A declining water level in Pactola Reservoir and nagging drought conditions have triggered a reduction in the water release flows from Pactola.

Effective Thursday, Oct.1, the Bureau of Reclamation is reducing the water release flows at Pactola Reservoir from 30 cubic feet per second (cfs) to 15 cfs for the upcoming winter season.

Thursday’s adjustment is timed to coincide with the end to irrigation season and is intended to maximize capacity and storage levels during another winter season with forecasted below-level moisture levels and decreased snow-pack in the water shed above Pactola Reservoir.

“In an effort to conserve water and keep as much in the reservoir as possible but also maintaining flows in Rapid Creek we felt we needed to look at our releases from Pactola,” Ron Bengs, Civil Engineer, Bureau of Reclamation, said.

Several factors lead to the decision to reduce the release from Pactola. Expected inflows to Pactola at this time of year would be 40 cfs, currently, inflows are 23 cfs. Also, South Dakota is in drought conditions and the weather service is forecasting a drier than normal winter.

“We just need to look at conserving water and yet maintain downstream flows for aquatic life and our downstream contractual requirements,” Bengs said.

Pactola Reservoir, constructed to help downstream communities cope with water uncertainties, is visibly low but still at 70 percent storage capacity.

Rapid City and Bureau of Reclamation officials hosted a press briefing Wednesday to outline Thursday’s pending action and assure community and area residents the storage level of Pactola Reservoir remains high.

As of Monday, Pactola Reservoir was at 70 percent capacity with storage levels exceeding 39,000-acre feet.

Eric Boyda, Water Superintendent, City of Rapid City, said the city was currently at alert status due to the reduced inflows into Pactola, not the water level of the reservoir.

“We have 70 percent of our storage capacity in Pactola and 90 percent in Deerfield. Those reservoirs were built to weather these droughts.” Boyda said. “This measure is likely going to save approximately 2 billion gallons of storage in Pactola. Everything is indicating this drought is going to continue and we’re going to have lower precipitation and lower snowpack into this upcoming year so maintaining that water in the reservoir is important for our long term strategy for providing water to the municipality.”

Thursday’s planned action is the latest response to continued impacts from summer drought conditions and lack of winter moisture. In March, the City of Rapid City initiated annual water conservation measures two months ahead of schedule. In August, the conservation measures were extended past September 30 to year-long restrictions. It is the second consecutive summer Rapid City has lengthened the period for water conservation measures.

The Bureau of Reclamation and the City of Rapid City has coordinated the water release adjustments with South Dakota Game, Fish and Parks officials in order to minimize impacts to fish populations and spawning trout.

Rapid City officials indicate the timing of the action is meant to coincide with the conclusion of the formal irrigation season, when down-stream irrigators call for adjustments in release flows for crops and livestock use as determined by existing water agreements.

City officials are also assuring the public that the lower releases from Pactola Reservoir are more than sufficient to provide adequate water supplies for residents.