Bowman Dam was completed by the US Bureau of Reclamation (BoR) in 1961, damming the Crooked River and creating Prineville reservoir. It was built to protect development downstream from flooding, including the City of Prineville, and to provide water for Ochoco Irrigation District (OID) who operates the dam. While these are worthy goals, Bowman Dam has also caused significant environmental damage. OID, Prineville, and Crook County would now like to add a small hydroelectric facility to the base of Bowman Dam and are asking for a waiver to the State of Oregon requirement that fish passage be provided at dams undergoing significant changes. This is a complex issue, below are my thoughts. The waiver application, supporting documents, and analysis by the Oregon Department of Fish & Wildlife can be found here. Public comment on the waiver application is being accepted until June 22nd.
Oregon law states that fish passage waivers can be granted if the applicants provide other benefits to fish and wildlife that are greater than the benefit of fish passage. The applicants state that the revenue generated from a small hydro plant is far less than the cost of providing fish passage making it economically unfeasible. ODFW’s analysis does not argue this point. The applicants propose that they instead provide a partial solution to the gas bubble disease problem, create artificial spawning beds in the Wild & Scenic section of the Crooked River, provide passage at a small dam adjacent to Prineville Golf Club on Ochoco Creek, and donate financial assistance for restoration work at the Deschutes Land Trust’s new Ochoco Preserve.
While examining each of these proposed actions, it is necessary to do it in the context of the environmental damage that Bowman has done.
Approximately 500 miles of habitat upstream of the dam has been made inaccessible to migratory fish. These include current populations of redband trout and mountain whitefish as well as locally extinct anadromous fish such as Chinook salmon and steelhead. In fact, studies have indicated that the Upper Crooked River watershed was once the single most important spawning habitat for steelhead and spring Chinook in the Deschutes Basin.
The recent completion of a ladder at Opal Springs at the mouth of the Crooked River clearly illustrates the importance of fish passage. In just the past few months, thousands of fish from many species have used the ladder to move up and down the lower Crooked River below Bowman Dam, reconnecting populations that had been cut off from one another for decades, and thereby improving the ecosystem.
Anyone who has visited the Wild & Scenic section of the Crooked River below Bowman Dam knows how murky the water is. This turbidity is due to extensive erosion above Prineville Reservoir coupled with a poor design of the dam outflow which is at a steep angle. Turbidity is one measure of water quality and the Crooked River violates Oregon Department of Environmental Quality (ODEQ) standards for it.
Separate from the fish passage requirement, ODEQ will require that the applicants address the turbidity problem which they plan to do by installing two Howell Bunger valves which can change the angle of the discharge, thereby reducing turbidity. The applicants go on to state that these valves will also reduce the very real problem of gas bubble disease in the Crooked. This appears to be a stretch.
The applicants waiver document as well as supporting analysis from BoR make it clear that the benefits from these valves will be at flows well under the 1,500* cubic feet per second (CFS) that ODFW has identified as the threshold for serious gas bubble disease in the Crooked and resulting dramatic population declines of native redband trout and other salmonids. The bottom line is that the Howell Bunger valves should ameliorate the turbidity issue as required by ODEQ but will be of little benefit to fish. In fact, BoR’s analysis says that the way to reduce gas bubble disease, even after the valves are installed, is to build a rock weir in the river downstream of Big Bend Campground, raising and slowing the river from the dam to the weir and allowing time for dissolved gasses to dissipate before they are passed downstream.
Side note: The law states that no measures required by a state agency other than ODFW can be used in the analysis of mitigation measures for a waiver. Thus, regardless of any benefit from the installation of the Howell Bunger valves, it is irrelevant for the ODFW analysis.
The other mitigation measures proposed by the applicants are certainly welcome. Bowman Dam has stopped the natural downstream migration of gravel suitable for spawning beds. Fish passage is seasonally blocked on Ochoco Creek downstream of Ochoco Reservoir. The Deschutes Land Trust’s Ochoco Preserve is limited, but important, habitat at the confluence of the Crooked River, McKay, and Ochoco Creeks. The problem is that these efforts are nowhere near providing a “greater benefit” to fish than providing passage at Bowman Dam.
From a financial perspective, the applicants estimate $300,000 a year in profits, or $15,000,000 after 50 years assuming no rate hikes. They state they will make a one-time donation of $200,000 for habitat restoration at Ochoco Preserve, $90,500 for passage at the small dam on Ochoco Creek, and between $265,000 and $471,000 on gravel over the next 50 years.**
On the other hand, the applicants state they cannot afford to install a fish ladder, the dam is already there, and the projects they propose will provide at least some benefits. So, why not give them the waiver? First, hydro projects are granted 50-year operating licenses. That means 50 years of profits to OID after minor expenditures on projects to secure the waiver. It also means another 50 years of no fish passage at Bowman Dam.
Secondly, the applicants can do more. The Crooked River suffers from consistent low water conditions outside of irrigation season and low water all year after the final irrigation withdrawal below the City of Prineville. The easiest way to provide real benefit would be to guarantee improved flows in the river. The river also suffers from low water quality from agricultural runoff, largely from farms that are members of OID. Improving on-farm water delivery systems and eliminating agricultural pollution in the Crooked would also provide significant habitat improvement for fish.
I encourage you to read the materials, come to your own conclusions, and submit comments to email@example.com before June 22nd.
* A previous version of this post stated that gas bubble disease impacts fish at 3,000 CFS. ODFW informs me that they see impacts beginning with flows at 1,500 CFS. The BoR analysis says the Howell Bunger valves will only be effective at reducing gas bubble disease at flows below 275 CFS. So, the result is the same: installing these valves will do little to reduce the impact of gas bubble disease on fish.
** A previous version of this post did not include some financial figures.