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See a Slideshow of the Restoration |
By Lauren Miura
First come the blasts: The thunderous sounds of more than 100 tons of explosives ripping through tightly packed soil.
Then, the water — more than 2,500 acres flooded.
This isn’t a scene from a Hollywood blockbuster. It’s the latest step in The Nature Conservancy’s efforts to restore wetlands on its Williamson River Delta Preserve in southern Oregon.
In a move to reverse the fate of two endangered fish species and to benefit other wildlife, the Conservancy on October 30 used explosives to breach two miles of levees along Upper Klamath Lake. Removing the levees is part of a larger project to restore the vast marsh wetlands that once dominated the Williamson River Delta.
"The recipe for restoring wetlands has one main step — add water," says Mark Stern, director of the Conservancy’s Klamath Basin program. “Re-connecting these historic wetlands to the lake will provide important habitat for two endangered fish, as well as other native fish and wildlife.”
'Like Dumping a Pet Fish in a Cold Tank'
Historically, the Williamson River piled sediments across the 7,000-acre Williamson River Delta before entering Upper Klamath Lake. In the 1950s, farmers built levees around the delta and channeled the river directly into the lake, converting the rich bottomland soils of the delta into farmland.
While the conversion of the delta was a boon to agriculture, native fish, habitat and water quality suffered. The shortnose sucker and the Lost River sucker were listed as endangered in 1988. Scientists blamed the loss of wetlands at the mouth of the Williamson River as a major factor in the species’ decline:
- The original wetlands had acted as rearing habitat for larval suckers after they were hatched 13 miles upstream. In the wetlands, newborn fish would grow in size and strength before entering Upper Klamath Lake to spend their adult lives.
- But after the wetlands were drained, newly hatched fish floated downstream in early spring and were dumped directly from the river into the lake — exposing the centimeter-long fish to cold water, predators, strong waves and other dangers.
“We’ve seen three-degree temperature differences between the river and the lake,” says Matt Barry, director of the Williamson River Delta Preserve. “It’s like bringing a fish home from the pet store and dumping it into a cold tank without letting it get acclimated.”
Restoring Wetlands, Recovering Fish
In the next few years after the levees are removed, marsh wetlands will reemerge on the preserve. The restoration of the Williamson River Delta will provide more than four miles of riparian marsh habitat along the river — and thousands of acres of wetland marsh along the lake.
“Helping more larval fish attain larger sizes before entering the lake will enable more fish to reach the next life stage," says Stern. "That increases the likelihood that more fish will become mature adults and contributes to the recovery of these endangered populations.”
And the wetlands restoration project will benefit more than endangered fish. Because wetlands act as natural filters for pollutants, water quality in Upper Klamath Lake is expected to improve. Increased water storage will help lake managers meet obligations to irrigators and downstream flows. The restored wetlands will also provide breeding habitat for thousands of waterfowl and water birds such as sandhill cranes and black terns.
Consensus over Conflict
The restoration of the Williamson River Delta also represents a victory for collaboration over confrontation — in a part of the country where water rights can be contentious.
The project began in 1995 when then-U.S. Senator Mark Hatfield convened a group of Klamath Basin stakeholders. He asked them for recommendations to help ease conflicts over water allocation for endangered fish and agriculture, and vowed to help make them happen. The catch: They had work together to present recommendations they all agreed on.
The stakeholders — everyone from farmers and conservationists to officials from utilities, Native American tribes, business and government — recommended that wetland habitat at the mouth of the Williamson River be restored to benefit endangered fish.
With the help of partners, the Conservancy took the lead in acquiring 7,000 acres — essentially the entire river delta. Over the past 10 years, the Conservancy and partners have completed pilot restoration projects at the site. Research indicates that wetland plants are quick to return after levees are removed, and that native fish are quick to use the newly formed habitats.
“We’ve seen literally thousands of larval and juvenile fish using these new wetlands in the first couple of years,” says Stern. “This has been very encouraging to all of us who have been involved since the beginning.”
Lauren Miura is a senior writer at The Nature Conservancy.
Nature picture credits (top to bottom, left to right): Video © The Nature Conservancy (Klamath River Basin levee explosions); maps © The Nature Conservancy.
