To provide habitat for endangered salmon and steelhead on a tributary of the Columbia River, Chelan County Public Utility District converted a nearby gravel pit into a series of ponds and then connected the ponds to the river. Initial observations show the ponds are providing a sanctuary for young fish, especially during high flows.
By Jennifer L. Burns and Steven C. Lachowicz
Habitat where young salmon and steelhead can hide from predators and escape high river flows has been disappearing as a result of development along the Columbia and Wenatchee rivers. One solution to this problem is to expand the ecosystem in the rivers’ floodplains, and then connect these improved areas to the river.
Such a spot existed along the floodplain of the Wenatchee River, a tributary of the Columbia. The spot – 8.8 acres of flood plain and riparian shoreline – is owned by the Washington Department of Fish and Wildlife (WDFW). Working with the state, Chelan County Public Utility District (PUD) converted the spot into a series of ponds, then connected the ponds to the Wenatchee River via a channel. The ponds provide a location where young salmon and steelhead can escape the perils of predators and seasonal high river flows. Since completion of the area, a variety of fish species have been observed in the ponds.
Two mineral oil spills
Oil spills and a better environment for fish are not topics that usually go together. But personnel at Chelan County PUD found a way to merge the two.
In November 1998, Chelan County PUD accidentally released 700 gallons of lightweight mineral oil into the Columbia River from its 1,287-MW Rocky Reach hydro project. The project is 7 miles upstream from the confluence of the Wenatchee River with the Columbia. Fish that use both rivers for spawning and rearing include federally listed endangered steelhead and chinook salmon. The PUD paid an initial fine of $1,500 in December 1998 but was continuing discussions with the Washington State Department of Ecology over whether an additional (amount undetermined) natural resource damage assessment would have to be paid.
Then, in August 2002, Chelan County PUD experienced a runner hub failure that resulted in the release of about 1,200 gallons of mineral oil from its 624-MW Rock Island facility into the Columbia River. Rock Island is about 17 miles downstream from Rocky Reach.
As discussions with state agencies continued regarding potential fines and damage assessments as a result of the two mineral oil spills, Chelan County PUD saw an opportunity to do more with the money.
Offering fish enhancement research
In March 2003, Chelan County PUD entered an innovative settlement agreement with the Washington State Department of Ecology. In lieu of paying the initial $10,000 fine for the Rock Island spill, the PUD would perform a feasibility study for a fish enhancement project. The site selected – along the Wenatchee River – previously had been identified by consultants hired by Chelan County PUD as a potential fish and wildlife habitat enhancement area.
The site, owned by the WDFW, consists of about 8.8. acres of flood plain and riparian shoreline. In April 2004, the Upper Columbia Salmon Recovery Funding Board (SRFB) identified the site as a high-priority location for restoring ecosystem function and connectivity within the riparian flood plain.
Results from the feasibility study, performed by Anchor Environmental LLC, convinced Chelan County PUD staff and the PUD Board of Commissioners that the site had excellent potential to provide endangered salmon habitat. Chelan County PUD decided to attempt a major enhancement project that would exceed the terms of the oil-spill settlement and satisfy the recommendations of the SRFB.
In 2004-2005, Chelan County PUD applied for and received grant funding from the SRFB and the National Fish and Wildlife Foundation. Total grant money received was $188,500. Chelan County PUD contributed funds of $34,000, which was the amount of the combined natural resource damage assessments from the Rocky Reach and Rock Island spills. Thus, the total budget for the project was $222,500. Chelan County PUD settled on this amount after completing an in-house survey, developing a preliminary design, calculating earth work quantities, and estimating the total project cost.
Moving forward with the enhancement
To make the fish enhancement project a reality, Chelan County PUD faced numerous challenges. These included accomplishing agency coordination and permitting, as well as designing and con- structing the project. Chelan County PUD embarked on the state permitting process in March 2005. Permits required included shoreline permits and in-river construction approval. The utility received final permit approval in September 2006.
During construction of the four ponds that make up the Dryden Fish Enhancement Project, woody debris and boulders were placed to provide suitable habitat for fish.
Initially, the challenge was to select an enhancement project design that would satisfy regulatory agencies and benefit fish. Extensive coordination and communication had to occur between the permitting agencies, regulatory agencies, local landowners, and stakeholders.
For example, obtaining grant funding required a series of public meetings describing the project and potential benefits to fish and wildlife. Chelan County PUD staff worked with engineers from WDFW to validate the groundwater source and refine the channel design. Chelan County PUD staff also met with regulatory and permitting agencies on site to facilitate cooperation. The state Department of Ecology participated in all stages of discussion to ensure Chelan County PUD’s obligations were met.
The resulting project was called the Dryden Fish Enhancement Project, named for the nearby community of Dryden. The design consists of a 640-foot-long series of ponds connected by a channel. The ponds are 4 to 10 feet deep and contain woody debris and boulders to provide suitable habitat for fish. Fish enter and exit the area via an inlet off the Wenatchee River.
During the design phase, the greatest challenge involved finding a water source for the series of channels and ponds. A typical up-river water inlet was not feasible because of seasonal high flows. The use of a pump station would have put the project significantly over budget.
As an alternative, Chelan County PUD staff investigated the possibility of using a self-feeding groundwater source. Rayfield Brothers Excavation worked with Chelan County PUD staff and engineers with WDFW to perform groundwater pump tests. Chelan County PUD staff monitored groundwater and river water elevations to establish a predictable and sustainable correlation with river flow. WDFW and Chelan County PUD engineers worked together to the water source was sustainable and would be virtually maintenance-free. Pump tests showed there was enough groundwater at the site to provide a secure supply for pools 4 to 10 feet deep, even when the Wenatchee River was not running at high levels. Tests also showed that the groundwater would serve as an excellent temperature control, keeping water in the channel cool enough for the species for whom the refuge was being designed.
Completing the work
Rayfield Brothers began construction in October 2006. Construction of the inland channel and pond system was completed in stages, rather than all at once, to minimize disturbance to riparian areas outside of the channel/pond footprint. First, a temporary construction road was built along the centerline of the new channel/pond system, to allow truck and equipment traffic. Once the temporary construction road was complete, Rayfield Brothers worked from the center of the road outward to construct the inlet channel and ponds. The soil did not have sufficient bearing capacity to support truck and equipment traffic. The temporary road in the center of the channel allowed work to occur in two locations simultaneously, without the need to access from outside the channel/pond footprint.
Keeping costs down represented a significant challenge for the project. The window available for construction, combined with permitting required by the U.S. Fish and Wildlife Service and the National Marine Fisheries Service, dictated that work be performed at a time of year when the river was increasing in flow. Rising water levels in the Wenatchee River, combined with the need to isolate the excavation from the river, contributed to additional costs. In particular, there was a need to unwater some areas.
Logs, rocks, foliage, and grasses were added or restored during construction of the Dryden Fish Enhancement Project to help the ponds blend with the environment and provide suitable habitat for fish.
To reduce overall cost, Chelan County PUD staff and contractors used materials available on-site or from property owned by the PUD. For example, logs and root wads were harvested from Chelan County PUD property during a clearing operation for a new substation. The site of the enhancement project was an old gravel pit, so abandoned boulders were used as anchors for the woody debris. Excavated material from the channels and ponds was processed on site and used as berm material.
Final construction of the inland channel, ponds, and inlet structure was completed in December 2006.
Ongoing evaluation and monitoring of the project will be a cooperative effort between WDFW, Chelan County PUD, and contractors hired by the PUD. Goals of the monitoring – to be performed for ten years – are to keep track of in-stream habitat use, fish numbers/ species, and water quality. Chelan PUD will use photos taken annually to document changes to riparian areas and channel morphology over time. Vegetation, in-stream fish habitat structures (with their performance during varying streamflow conditions), and use by salmon will be monitored.
Results to date
Although Chelan County PUD has not initiated monitoring, a variety of fish species have been observed in the newly created off-channel habitat, including chinook fry, dace, and some yearling steelhead parr. These fish were observed taking refuge from seasonal high flows in the Wenatchee River from mid-April through early July 2007.
In October 2007, Chelan County PUD staff planned to complete the project by planting shoreline vegetation, including grasses, sedges, cottonwood, hawthorne, red osier dogwood, willow, ponderosa pine, and snowberry. Once this vegetation has matured in three to ten years, the project is expected to provide low-velocity habitat from April through July, a cool water refuge during the summer (mid-July to September) when water temperatures in the main river can be warmer than desired for salmon and steelhead, and possibly some over-winter habitat.
Ms. Burns and Mr. Lachowicz may be reached at Chelan County Public Utility District, 327 North Wenatchee Avenue, Wenatchee, WA 98801; (1) 509-661-4474 (Burns) or (1) 509-661-4639 (Lachowicz); E-mail: [email protected] org or [email protected]
Jennifer Burns is environmental coordinator and Steve Lachowicz is communications director with Chelan County Public Utility District.