MONTE VISTA — Colorado Parks and Wildlife implemented a mandatory closure to fishing at Home Lake State Wildlife Area effective June 2-16.

The closure was authorized Friday afternoon, June 2, after testing the lake water due to chemical exposure. According to published reports, CPW is looking into whether an errant crop-duster may have been the cause of the exposure.

The closure was recommended by the Colorado Department of Public Health and Environment. The direct cause of the chemical exposure is being investigated by multiple agencies, including CPW and the Colorado Department of Agriculture.

“Our early sampling has indicated that two herbicides used for agriculture have made their way onto the vegetation on the south end of the property and into the water,” said CPW Area Wildlife Manager Rick Basagoitia. “Out of an abundance of caution, we will halt fishing for a couple of weeks as we determine the appropriate course of action and monitor the affected areas.”

According to published reports, one of the chemicals was Flumioxazin, a broad-spectrum herbicide used to control select grasses and broadleaf weeds.

CPW will continue to sample the water and determine impacts in the reservoir. The herbicides detected can be toxic to aquatic life.

“We haven’t seen stressed fish or a die off so far, just the dead snails along the shore,” said CPW Aquatic Biologist Estevan Vigil. “But we want to warn the public not to consume any fish from this lake at this time.”

Home Lake State Wildlife Area is located approximately 1½ miles east of Monte Vista and shares a boundary with Shriver & Wright State Wildlife Area and Rio Grande State Wildlife Area. It offers fishing for rainbow trout, channel catfish, largemouth bass, bluegill, and grass carp.

“Thankfully, this does not appear to have impacted those other two properties,” Basagoitia said. “The swath is approximately a mile but doesn’t seem to have extended to other properties. As part of the investigation, we will continue to monitor how far this does extend.”

CPW has limited the amount of water exiting Home Lake to prevent any further impacts downstream.

The lake will be marked with closure signs. The two-week closure will allow CPW and partnering agencies to monitor and sample the water to determine the extent of the exposure. It is possible the closure will be extended.