SALIDA — Despite fine fishing on the Arkansas River just outside the conference hall, the action among anglers took place indoors at Friday’s Colorado Wildlife Commission workshop.

The commission dedicated the day solely to public commentary on two controversial transmountain water diversion projects proposed for Colorado River headwaters, and river advocates crammed the docket with impassioned pleas for assurance that the projects won’t decimate fragile fisheries such as the Fraser River, Williams Fork, Blue River and the Upper Colorado itself.

They came away with none.

In fairness, the commission is only about halfway through the window to evaluate plans to mitigate impacts to fish and wildlife habitat affected by the proposed Moffat Collection System and Windy Gap Firming projects. And there is no quick fix for the complex pair of proposals that could result in 80 percent of native flows being diverted from the Upper Colorado basin for municipal use along the Front Range.

So the commission got an earful.

Representatives from Grand County, Trout Unlimited, Northwest Colorado Council of Governments, Colorado River Landowners and Western Resource Advocates expressed concerns over the proposals by the Northern Colorado Water Conservancy District to annually draw thousands of acre-feet more water from Windy Gap Reservoir for Front Range storage and by Denver Water to increase diversions through the Moffat Tunnel to an enlarged Gross Reservoir near Boulder.

Already-depleted rivers have seen increased water temperatures, insufficient flushing flows, nutrient loading and declines in aquatic species ranging from mayflies and stoneflies to sculpin and trout. Concern abounds that impacts of the projects will magnify the problems.

“I see dead brown trout on the bank every year in August because the water temperatures are too high,” said rancher Ron Jones, whose Fraser River frontage merits Gold Medal designation. “If they want to take the water, then they should put the money into doing what it takes to protect the rivers.”

It’s an interesting perspective — putting the health of the rivers ahead of the perceived need for more water elsewhere. There is some money on the table dedicated to enhancement of a portion of the Colorado, but consensus holds that it’s not nearly enough. And as currently proposed, many mitigation measures are conditional upon the volume of water already diverted and stored in East Slope reservoirs, not necessarily what’s happening in the rivers it’s being drawn from.

“It should be a shared risk between the river and the project,” said Scott Pfeifer of Resource Engineering in Glenwood. “Not just the river.”

As Jones points out, often lost in the jumble of science, math and engineering is the reality that such water diversions ultimately amount to business decisions. And the water districts are some hard-nosed negotiators on the brink of closing a pretty sweet deal for themselves.

“We’ve presented what we think is a fair and reasonable plan,” Windy Gap project manager Jeff Drager said. “I won’t say that’s all we will do, but our participants feel it’s pretty close to the max.”

The Wildlife Commission, meanwhile, finds itself in the compromising position of attempting to address flaws it has identified in the proposals and finding a way to enforce its stance in the next month. After that, the Colorado Water Conservation Board will have 60 days to affirm or modify the commission’s recommendation as the state’s official position.

Scott Willoughby: 303-954-1993 or swilloughby@denverpost.com