Somewhat small in stature at just about 250 miles in length, the Yampa River that flows through Dinosaur National Monument is significant not just for its white-water rapids but for its unbridled flows. Not a single dam stands in the way of this river famous with rafters and anglers and the lifeblood for four species of endangered fish.

Given life from snowmelt gathered in and around the Flat Tops Wilderness of northwestern Colorado and then coursing west to its confluence with the mightier Green River, the Yampa is honored as the last major tributary of the Colorado River system that isn't impeded by a dam.

There are growing concerns, though, that proposed water diversions to feed not only an oil-shale operation but also to sate growing communities along Colorado's Front Range could greatly affect the river flows.

Back in December 2006 the Northern Colorado Water Conservancy District described (see attachment) a $3 billion-$4 billion diversion project that could tap 300,000 acre-feet from the Yampa annually to send over to Denver and other Front Range communities.

More recently, Shell Frontier Oil and Gas, Inc., this past December applied for permission to suck 375 cubic feet of water per second from the Yampa to put into a reservoir that could hold 45,000 acre-feet of water for a future oil-shale project.

In February, the federal government, on the behalf of the U.S. Bureau of Land Management, the National Park Service, and the U.S. Fish and Wildlife Service, filed its "statement of opposition" to Shell's project. For now, though, there are more unknowns than knowns.

"We’re just trying to get a handle on everything, all the proposals right now," said Mary Risser, superintendent at Dinosaur National Monument. "The Shell (application) is the most recent. ... There’s potential implications for the Ouray fish hatchery downstream in Utah. Dinosaur itself doesn’t have in-stream flow water rights (to protect fisheries), but we do have water rights for other water, for surface diversions and some shallow groundwater wells that are dependent on the stream flows.

"Basically, the application didn’t contain a lot of information that would be sufficient for us to look at the full ramifications of the project.”

Among the "knowns" is that Shell wants to build a pumping plant along the Yampa and store the water in the proposed Cedar Springs Draw Reservoir. Both the pump station and reservoir sites are on BLM lands, and as such the oil company would have to follow National Environmental Policy Act guidelines in applying for permission to construct both. Currently, Shell has not applied for a right-of-way to those sites.

As for the diversion and shallow groundwater rights held by the federal government for Dinosaur, they "may be adversely affected if the application is granted, or is granted without adequate protective terms and conditions," according to the government's statement of opposition.

Now, years ago the Fish and Wildlife Service listed the humpback chub, bonytail, Colorado pikeminnow, and razorback sucker as endangered species under the Endangered Species Act. How the Yampa's water flows are impacted is of importance to the survival of those species, at least in the Yampa.

"We don’t have sufficient information to really look at what the risks to the park is," said Superintendent Risser. "There’s the potential that any kind of diversions could adversely affect our natural, cultural, and recreational resources. And so by participating in this, by filing the statement of opposition, it gets us a seat at the table so we can find out what’s going on.”

The rafting industry also is concerned, saying Shell's claim alone could impact their ability to float the river at certain times.

Another major uncertainty at this time is how such diversions would affect the Colorado River Compact, which apportions water throughout the seven-state Colorado River basin.

To get a sense of this river, its values, and the threats, watch the following 16-minute video. And for more information, follow the Yampa River Awareness Project.