BILLINGS (AP) — The Montana Department of Fish, Wildlife & Parks approved a plan to drain a lake to kill an invasive species of clams.

The state approved the plan to drain the area in Lake Elmo State Park in Billings in September.

The Asian clams in Lake Elmo can reproduce quickly and in large enough numbers to clog irrigation and municipal water systems.

The lake would be refilled in spring 2022 and restocked with game fish. The project has a $750,000 projected cost and the state is seeking partners to help fund the work.

Asian clams filter out water nutrients necessary to support desirable fish and organisms in the food chain, officials said.

The clams were discovered in Lake Elmo in 2019. Subsequent searches of an irrigation storage reservoir and ditches and rivers upstream and downstream found no other clams.

The clams are not found elsewhere in Montana and wildlife officials were unsure how they entered the lake.

Officials are concerned that, if left unchecked, the clams could spread to the Yellowstone River and beyond.