Article written by: Matthew Oates
As we know them, Southern California’s rivers are shaped by dams. For decades, they controlled water for cattle and agriculture, some generated electricity, and almost all created reservoirs. However, a statewide movement is getting bigger and louder, calling for the removal of dams in order to restore native ecosystems and save species. With the removals, we have to balance human needs with environmental sustainability.
The rivers of Southern California- the Santa Ana, Los Angeles, and Ventura Rivers once flowed to the Pacific Ocean freely. Today, they’re fragmented and often stagnant, their natural rhythms disrupted by dams. They block sediment, alter water temperatures, and prevent fish from reaching upstream, a critical part of their breeding process. These come with big consequences: affecting our watersheds, the wildlife, the plants, and even people who depend on those systems. While originally constructed to control flooding and hold water for agriculture and urban supplies, dams have caused great devastation that cannot be looked at lightly.
The clearest case of what was lost would be the steelhead trout. These fish once moved freely between the ocean and freshwater streams, but their route has now been severed. In places such as the Ventura River, there are only a few which could be found where there used to be thousands. But they’re more than fish-they’re an indication of a river’s well-being. When steelhead trout are in short supply, that means it is a signal for something wrong with the river itself. For those battling to take out dams, the trout have become a symbol of why this work matters. Dams kill fish, and therefore they kill rivers. But taking out dams isn’t as simple as just knocking them down.
It’s a huge, expensive, and extremely complicated process. Take Matilija Dam in Ventura County, for example. The removal effort has been running for years, with plans to again let sediment flow freely and restore lost habitats downstream. But challenge upon challenge has beset such plans. What do you do with the water when it’s in flow? Diversion works, but it only works for so long: especially with the massive spring rainfall, these projects are forced to pause and lose progress all at once. But it pays off. This is not only good for the fish, but it restores beaches, rejuvenates plants, and an entire ecosystem starts to come back. It’s argued that taking out the dam is one of the most powerful ways to reverse the effects of decades of river management. But as is true for everything, not everyone is on board.
Dams provide drinking water, water for agriculture, and water for recreation. It feels precarious to tear them down in a place like Southern California, where droughts are the norm and water demand is always high. What if, for some reason, we lose access to the Colorado River’s supplies? There’s also the question of what happens to all the sediment trapped behind these dams. If it’s released too quickly, it could cause damage downstream. And of course, the cost. Removing dams is expensive, and it takes years of planning, permits, and negotiations to make it happen. Still, with climate change only speeding up, the argument for dam removal is gaining momentum. Dams, once solutions, are now part of the problem. They’ve lost their usefulness; we have water in our pipes. They trap sediment that should be replenishing beaches, heat up water to unhealthy levels (leads to bacteria), and block migration routes for fish that are already hanging on by a thread. Letting rivers flow naturally again could make them more resilient to the extreme weather patterns we’re starting to see more often.