A 7.2-mile section of the Rio Grande in Colorado dried up, ironically as part of a river restoration project that obviously didn’t unfold as intended. The dewatering of this stretch of river caused a fish kill that biologists can’t exactly quantify, but say it’s safe to assume that this part of the fishery won’t recover for likely three to five years.
According to reporting in the Alamosa Citizen, the 7.2-mile section of the Rio Grande was located along the North Branch, east of Del Norte, but just below the Gold Medal section that lies between Del Norte and South Fork. That section of the river didn’t suffer any dewatering or fish kills, according to biologists.
The fish kill was caused by a river restoration project that’s part of the Rio Grande Headwaters Restoration Project. This problem lies with the Farmers Union Canal Project, a job that was slated to modernize canals and headgates, in the area. A decision was made to cut off flows for work on the project, which coincided with one of the few cold snaps seen in the Rockies this winter.
That led to pools freezing solid, suffocating fish in areas where the water was deep. In other areas, the river simply quit flowing. Citizens and landowners along the effected stretch of river say that scavengers made off with more fish than Colorado Parks & Wildlife (CPW) biologists could include in their count of dead fish. Fish up to 24 inches long have been found dead.
CPW hasn’t filed an official ruling on its investigation, so there’s no one to blame yet for the fish kill. But biologists were frank in their assessment that it would take a half-decade for this stretch of river to recover. Not only were trout killed, but aquatic insects like mayflies, caddis, stoneflies, and midges were killed as well, along with native, threatened species that have been in the Rio Grande long before trout showed up.