This endangered kangaroo rat needs floods to survive. A new agreement may save it

Good news for two imperiled species found only in Southern California: Wildlife groups and local water agencies have reached an agreement to protect the habitats of the San Bernardino kangaroo rat and Santa Ana sucker fish.

The two species used to be found widely in the region. But construction, flood management systems and other human development has largely destroyed their habitats.

What can be done?

Well, reverting the species’ habitat to a completely natural state is not on the table. To do that would require the removal of the Seven Oaks Dam in Highland, which is used to mitigate floods for communities farther down the Santa Ana River like San Bernardino.

Seven Oaks Dam is 550-foot-high and 2,980-foot long. The project, designed to control flooding on the Santa Ana river, was completed in 1999.

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Courtesy OC Public Works

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Advocates say the restoration efforts instead will create a new management system to keep the species alive. Dan Silver, whose group Endangered Habitats League was one of the parties in the lawsuit that led to this week’s agreement, said the approach will be experimental.

Why some species need floods

You might think of flooding as something that destroys habitats instead of creating them. In many cases you’d be right — but contrary to what we see today, the natural rivers in California’s coastal sage and chaparral habitat used to flood and eventually change course over centuries.

And these are just two of the native species that adapted to live alongside Southern California’s periodic flooding. The Santa Ana sucker is able to rebuild populations quickly after massive floods, and San Bernardino kangaroo rats actually need regular flooding in order to survive.

Where things stand with kangaroo rats

The rats, which get their name because of their two-legged stance and large haunches, eat mostly seeds and are dependent on new plant growth to survive. That puts their needs at odds with how California manages floods by controlling where the water goes. If plant growth is mature — an indication that rivers are able to maintain their course — it’s no longer a suitable habitat for the species.

Flood risk management like dams and concretized channels are creating isolated populations of the species, Silver said.

“There's three populations. They're isolated from each other,” Silver said. “So the animal has a genetic challenge with the inbreeding that happens when you have isolated populations.”

The result is a species Silver says is “fairly far down the road to extinction.”

“It's going to take active human management to make sure that doesn't happen,” Silver said. “I wish we could just say, ‘Well, let's just set aside the land and let it alone. It'll be fine.’ But that's often not the case. You do need active management to restore it and to manage it.”

Where things stand with the Santa Ana sucker

The Santa Ana sucker, which lives downstream from the protected area for the San Bernardino kangaroo rat, has also seen dwindling populations due to development.

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Kai Palenscar

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Courtesy U.S. Geological Survey

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The Santa Ana sucker is doing a bit better as a species — so far, it’s only listed as threatened under the Endangered Species Act, while the San Bernardino kangaroo rat has been considered endangered since 1998.

Still, the fish’s habitat has also been dwindling due to human development, and conservation advocates and water agencies hope that the protections will also help the sucker fish downstream in other parts of the Santa Ana river.

What the settlement calls for

As part of the agreement, which was reached on Aug. 29, county officials will work with environmental groups to determine the specific plan of action, including where and how to reintroduce water into the remaining habitat to mimic natural conditions for the San Bernardino kangaroo rat.

“Our agreement calls for 400 acres to be restored over time, but that's a floor, it's not a ceiling,” Silver said. “If things go well, we can do more.”

The current efforts to preserve the species’ habitat started in 2016, when the Center for Biological Diversity and the Endangered Habitats League filed a lawsuit against the U.S. Army Corps of Engineers, who constructed the dam as part of an ambitious flood control project on the Santa Ana River. Silver stressed that all parties wanted to reach a settlement rather than litigating it in court.

“These flood control districts and the water districts are becoming more environmentally conscious,” Silver said. “We need these infrastructure agencies to step up to the environmental challenges and try to improve things, particularly when the infrastructure caused damage in the first place. It's part of a cultural shift that's ongoing, and we think that our settlement agreement can accelerate that.”

Public agency officials echoed these sentiments following the settlement.

“This agreement recognizes that a piece of public infrastructure can be managed for multiple public benefits and provide the true win-win-win that our shared taxpayers expect from public agencies,” said Heather Dyer, CEO and general manager of the San Bernardino Valley water agency, in a statement. “By working together, I am confident that we can achieve tremendous benefits for generations to come.”

Why it matters

The benefits aren’t just for the threatened animals — as long as the water supply permits, the agreement will also help recharge local aquifers at a rate of up to 500 cubic feet per second, according to San Bernardino Valley. Native plants will also reap the benefits of a habitat that more closely matches the natural environment they evolved to live in.

“This agreement shows that with cooperation, we can achieve wildlife protection, water conservation and flood safeguards for Southern California’s largest watershed,” John Buse, a senior counsel at the Center for Biological Diversity, said in a statement.