Forgotten pipe could remedy mudflats

McPhee ponds designed to be filled, but jurisdiction is unclear

Sam Green/Cortez Journal Richard Carpenter enjoys fishing in the Dolores near the inlet pipe for the two ponds by Dolores.


In the early 1980s, before McPhee Reservoir was completed and filled, Dolores prepared to become a lakeside community.

Realizing that fluctuating lake levels would create a large mudflat outside town when the lake was low, the town took action. The town negotiated with the Bureau of Reclamation to build two ponds at the Dolores end of the reservoir to hold water and prevent a muddy eyesore at the entrance to town.

To fill the ponds, a headgate and pipe were installed from where the Dolores River flows nearby. Boulders positioned at the intake to back up water into the pipe have subsided.

The filling system has a minor design flaw and needs additional maintenance. Who is responsible for it is unknown.

"It was designed so you could run fresh water into those ponds," said John Porter, the reservoir's first general manager. "When I tried to open it up during a dry year, it was rusted shut."

Porter, who has since retired, said it was never an issue because the lake would always fill up to the established shoreline, flooding the ponds with water.

Then 2002 came, the driest since the reservoir filled in 1987.

During normal water years, the reservoir backs up into the ponds. As the lake receded from irrigation demand, the ponds did their job holding water, creating aesthetic benefits, and providing fish habitat and fishing access.

But persistent dry, hot summers have depleted the reservoir and the ponds near Dolores, creating stagnant water, algae blooms, and the mudflats they were designed to avoid.

Who has jurisdiction and responsibility of the head gate operation is not clear. Several agencies help manage McPhee Reservoir, but a recent survey of agencies revealed no one is sure who is responsible for operating and maintaining the structure.

The Bureau of Reclamation owns the infrastructure, including the dams and canals.

The Dolores Water Conservancy District manages the lake for irrigation. The U.S. Forest Service manages recreation on and around the lake, including the exposed lake bed. And Colorado Parks and Wildlife controls the sport fishery and boat registration.

"The ponds were put in for the benefit of Dolores, but who controls that headgate is a good question," said Mike Preston, general manager for DWCD. "It is probably in a document somewhere and we will look into it."

As a result of the Dolores Star investigation, a tour of the headgate and pipe was conducted Tuesday afternoon by DWCD officials. The headgate was found to be open, but the river level was too low to enter the pipe, reported Ken Curtis, a DWCD engineer.

"It's basically functioning but it is partially plugged with mud and weeds," he said. "For the river to enter the pipe there, it would have to be running 200 cfs (cubic feet per second), which does not happen very often right there."

The system could possibly be improved if boulders were placed to back up the water enough to flow into the pipe. A search of documents by water officials did not reveal who is responsible for maintaining the system.

"Everything else was assigned, but that we can't find," Curtis said. "No one has thought of a maintenance responsibility document."

Dolores Mayor Val Truelsen believes it is the Bureau of Reclamation's responsibility.

"The headgate and ponds are outside town limits, and they are not owned by the town," he said. "They were built by the bureau."

"People have asked me, 'Why don't we fill those ponds?'" said Town Trustee Ginger Swope.

Reservoir officials said filling the ponds does not present water-rights issues. For it to work properly, a partial rock dam would need to be built up at the intake so river water could reach the pipe. Also build up of sediment in the ponds and pipe could require mitigation.

"I always thought the head gate should just remain open," Porter said. "It was part of a request by Dolores help prevent that mudflat from forming there."