RAPID CITY, S.D. – A decreasing water level in Pactola Reservoir has prompted the City to implement year-round water restrictions for Rapid City.

On Tuesday, Public Works Director Mike Theis told the Public Works Committee that the water restriction status for Rapid City would be elevated from “Concern Status” to “Alert Status” next week to accommodate water levels in Rapid City’s main source of water.

Rapid City gets about 85 percent of its water from Pactola and 15 percent from wells. Water from Pactola serves Rapid City and several downstream interests. Pactola is currently at 73.4 percent full with inflow at 6.4 cubic feet per second and outflow at 69 cubic feet per second.

“It’s concerning, we’re not in dire straits by any means at this point,” Public Works Director Mike Theis said. “We’re not seeing the water level coming in and we’re seeing a huge outflow going out. That’s the biggest concern right now.”

Alert Status is implemented when Pactola contains less the 26,950-acre feet of water and inflows are less than 50 percent of the mean monthly average. The water restrictions under Alert Status are similar to Concern Status although they apply year-round, rather than expiring on Sept. 30 as the Concern Status will.

“Assuming we don’t have any big changes in moisture patterns, inflows into Pactola, we would leave that in place through the winter months,” Theis said. “That will be a year-round restriction as long as we still have concern about water levels in Pactola.”

There are different designations for levels of water in Pactola and the reservoir is currently in Active Conservation level with a current elevation of 4,560 feet. Theis said the city has seen similar levels over the years.

“Pactola is considered full when it’s at the top of that Active Conservation level,” Theis said. “So, we’re about 20 feet down from that at this point… This is part of a normal pattern for us. We’ve seen this in years past, too, multiple times where we fluctuate up and down.”

Pactola Reservoir is currently about 20 feet below the desired top of Active Conservation level prompting new water restrictions in Rapid City.