Dolores river group seeks solutions
By Carolyn Dunmire
|'As the River Flows': A rafting-season chronicle|
For the past three years, a dedicated group of community leaders has been meeting to discuss ways to manage the Dolores River that will benefit fish, wildlife and human beings.
They have learned a lot — and one thing they’ve learned is that managing the “River of Sorrows” will continue to be anything but easy.
The group, called the Dolores River Dialogue, consists of representatives from all of the local and regional water managers as well as environmental groups, recreationists, and others. The group was convened jointly by the Dolores Water Conservancy District and San Juan Citizens Alliance to improve the environment of the Dolores River downstream from McPhee Dam while protecting or enhancing human uses of the river.
Their first meeting was held in January 2004. Since then the group has meet regularly to identify “doable” solutions for meeting fish and riparianhabitat needs. Despite the diverse and competing interests represented around the table, dialogue has continued.
However, the DRD is reaching a critical juncture. The science and hydrological research have been assembled and the time has come to start evaluating management options. Will the participants have enough courage to see these options through?
A plan to proceed
The first major task completed by the DRD was a “Plan to Proceed” — a blueprint of how the group would get to the point where it could decide what, if any, action to take to implement its goals.
Some facts about the Dolores
First, it had to have data: an analysis of water availability downstream of McPhee Reservoir; an environmental analysis of how different river-flow patterns would affect downstream riparian habitat, fish, and wildlife; and a correlation between water availability and environment, with a “matrix of options” that outlines the impacts of different release patterns.
With the release of a draft correlation report at the group’s last meeting in March, the “Plan to Proceed” is essentially complete.
Native fish a concern
The correlation report includes a summary of the hydrologic and scientific findings for the Dolores River. The DRD did not have funding to conduct any primary research and had to rely on existing data.
However, a great deal of research was available. The Colorado Division of Wildlife has been doing regular fish population studies on sections of the Dolores for 20 years. Records of river flows go back to 1928.
The construction of McPhee Dam initiated a flurry of studies on the Dolores River’s ecology and wildlife. (If only that flurry of paper were snowflakes, the DRD would not need to worry about downstream flows.) The major accomplishment of the group was to compile this avalanche of data into a useful format.
Still, there are things that aren’t known.
David Graf of the DOW, one of the authors of the correlation report, noted there is insufficient information about native fish. “We were clearly able to show how little we know about the three native fish species of concern in the Dolores River [the flannelmouth sucker, bluehead sucker, and roundtail chub].
“Overlaying and compiling all of the fish-related data we have suggests the suckers are truly not doing well since dam closure,” he said, “but it's only scratching the surface due to the lack of sampling sites river-wide and because we can only speculate why this might be occurring.
“The roundtail chub, being more of a generalist, seems to be hanging on, but again, data is a bit thin, especially for hard-to-sample areas such as Slickrock Canyon or the stretch below the Pyramid to Disappointment Creek.”
While not all of the findings are negative, overall the Dolores River is not supporting the riparian habitat or fish populations that it once did. And this is primarily due to lack of river flows.
Furthermore, the modeling done mainly by John Porter, former general manager of the Dolores Water Conservancy District, in 2006 suggested that McPhee Reservoir would fill and result in spills for 55 percent of the modeled years (more often than every other year). This is not playing out in reality and ratchets up the stakes for the DRD.
Water for the Dolores River is not as available as it once was.
Since the construction of McPhee Dam, Dolores River flows have been managed by the Dolores Water Conservancy District under the direction of the Bureau of Reclamation.
However, the Dolores River actually has been managed for more than 100 years. Irrigation diversions from the Dolores started in the 1870s. The Montezuma Valley Irrigation Company built its Main Canal No. 1 in 1898. MVIC holds some of the most senior water rights on the Dolores and controls 800 cubic feet per second, or the entire flow of the Dolores River in an average year.
The DWCD manages the Dolores River to meet objectives specified by the bureau. These include:
• Fill the reservoir when possible.
• Manage releases to provide whitewater boating opportunities, when possible. Try to peak releases on Memorial Day weekend and provide a minimum of 800 CFS for as long as possible.
• Try to limit outflows to less than 4,000 CFS to avoid using the emergency spillway.
Operation of the reservoir is decided by the bureau based on daily inflow and irrigation forecasts. Generally, the goal is to fill the reservoir and then match daily inflow with daily outflow (irrigation plus releases to the river).
But forecasts are based on incomplete and highly variable information such as “sno-tel” readings that measure the water content of the snowpack feeding the Dolores River.
Irrigation demand can change daily, depending on soil moisture, humidity, and farm operations. Vern Harrell field officer for the Bureau of Reclamation, concedes that the “small spills” are the hardest to predict.
The past two years have presented just those cases. In 2006, McPhee Reservoir did not quite fill, leaving rafters without a boating season.
This year, according to Harrell, the inflow forecasts were 30 percent low, causing the bureau to scramble to release water with little notice to rafters and great uncertainty about the amount of water that would be released because of fluctuating irrigation demands.
While the boaters are getting a limited rafting season, everybody has been frustrated by the lack of notice and the inconsistency in flows.
As the real Dolores River is turning out to be much drier and more unpredictable than model river flows, identifying “doable alternatives” could prove to be an interesting but futile exercise for the DRD.
An “alternative” is a description of a flow regime in the river — for instance, increasing dam releases and river flows in April and reducing them in May. The group’s core team has developed an analysis tool to evaluate the potential impacts of any alternative on geomorphology, riparian ecology, and coldand warm-water fisheries.
But real alternatives are proving more difficult to find than “doable” ones.
For example, in the March 2007 DRD meeting, a simple alternative such as “finding” a few thousand acre-feet to ensure a good flow for fish-sampling during May in the hard-to-reach sites came up. At that time, run-off forecasts did not predict a dam release.
While the irrigators “went on record” that they would be flexible to support needed river flows, they are opposed to releasing any downstream water not already designated for fish. Thus, the only real alternative is to shift the schedule of fish flows to fit the sampling window – perhaps shorting fish water needs later in the summer.
Graf said that other than evaluating annual tradeoffs, the group hasn’t used its “matrix of doable alternatives” on “anything particularly significant that could affect ecological resources below the dam.”
But, he added, “I am optimistic that as we evolve as a group and refine how the tool can be used, we will be able to look at big-picture alternatives to target specific interests downstream.”
And it looks like those interests will be native fish.
According to Graf, 13 miles of electroshocking from the Pyramid to just above Disappointment Creek found only one bluehead sucker, only four large and one juvenile flannelmouth, and scattered age classes of roundtail chub, but very few. Brown trout and smallmouth bass were plentiful, which is bad because they compete with natives.
If this goes on, the DRD will have to evaluate options to improve habitat and growth conditions for the fish. These could include increasing instream-flow levels in summer as well as releasing water at different times of year to facilitate fish movement and spawning.
The Dolores River Dialogue is at a point where more data and tools are not going to help. The question of how to make real water appear in the river is going to tap the intangible resources that have been built over three years – trust, creative thinking, and understanding of the limitations and opportunities the Dolores River offers us all.