Colorado Parks and Wildlife Proposed New River Standards

The agency aims to update water temperature rules for the Arkansas River below the Pueblo Dam.

Updated on Sept. 25, 2026 in Current Conditions

Colorado Parks and Wildlife Proposed New River Standards

Live Poll

Should environmental water temperature standards be relaxed to accommodate local hatchery operations?

Colorado Parks and Wildlife has proposed new ambient-based water temperature standards for the Arkansas River below Pueblo Dam. The change would apply specifically to the period of July through December.

Why it matters

The agency stated that current regulations do not align with actual observed temperatures in the second half of the year. Updating these standards is necessary to ensure they remain achievable while the Pueblo State Fish Hatchery continues its operations.

The proposed ambient-based standards were developed following a ten-year analysis of river temperatures. This study utilized temperature loggers and U.S. Geological Survey monitoring data to inform the new policy for the July through December timeframe.

The players

Colorado Parks and Wildlife

This state agency manages wildlife and outdoor recreation across Colorado, including the oversight of state fish hatcheries and river health.

Pueblo State Fish Hatchery

This facility supports local trout populations in the Arkansas River through active stocking programs.

The details

The Arkansas River below the dam supports rainbow and brown trout populations, which are bolstered by stocking from the Pueblo State Fish Hatchery. Because the hatchery contributes heat to the river water, the agency is also working with an engineering firm to mitigate the facility's thermal impact.

January through June: Existing water temperature standards remain in effect.
July through December: Proposed new ambient-based water temperature standards would apply.

Seasonal Patterns

The proposal follows a pattern set by using the U.S. Geological Survey monitoring network data to inform local ecological policy adjustments. These shifts reflect efforts to reconcile fixed biological standards with the measurable thermal fluctuations observed over the last decade.

Residents and stakeholders can participate in the discussion regarding these new standards at public meetings held at Lake Pueblo State Park. The proposed changes aim to balance sustainable trout populations with the continued operational viability of the local fish hatchery.

The takeaway

Adjusting water temperature standards to match ambient historical data ensures that regulatory requirements remain grounded in reality. This approach allows conservation efforts to continue effectively without placing impossible constraints on the local fish hatchery.