Protect our streams
I want to thank Friends of Rivers and Renewables for bringing Harvey Locke and Ric Hauer to town. Ric is one of the world’s foremost stream ecologists and a leader in how we understand rivers. They spoke at the Aspen Center for Environmental Studies last week about climate change and stream ecology.
We learned that the ideas of stream function from the past will not suffice to keep streams healthy in the future. Climate change will seriously degrade the resilience of stream ecosystems. Biodiversity will be reduced as rivers deteriorate from the changing conditions. And river ecosystems are perhaps the most important in our landscape. Rivers are the backbone of our watersheds. Injury is borne differently in different places, but injury to the river has far greater consequences.
Streams are extraordinary in their dynamic complexity. They are not just simple channels that deliver water in an engineered world. Yet that is the simplistic model of stream protection we use. The concept of minimum flows and the simple metrics used to measure “health” do not give a true picture of how real streams function. We’ve learned a lot in the past 20 years, but our policies remain ignorant.
Streams are far more than just the visible channel. The entire valley floor, filled with alluvial gravels, riparian forests and unseen water pulsing through in a complex dance is the real river. The real river is flowing through the gravel and roots just a few inches below the ground and yet might be a long distance from the channel. The channel we see is just a small expression of the whole, although we mistakenly think that’s all there is. There are whole populations of insects living in the underground gravels. These insects and these invisible habitats were completely unknown when we developed the simplistic and inadequate protective standards of minimum streamflows.
It’s time we see our streams as they truly are. We must then develop real protections for these backbones of our home landscape. Damage from climate change and altered flows might not become apparent for many years. Using the policies and methods of the past to protect the future, when we know these are no longer valid, won’t work. We need to understand the hydrology and whole river geomorphology of streams much better than we do now.
We know that minimum flows are not enough. We know that streams are dynamic and complex systems extending far beyond the visible channel. We know that these systems move and change over many years. We know that the riparian zones are an integral and fragile part of the stream ecosystem. We know that simple engineering solutions focused on the channel do not protect streams.
We need to know more about our home streams and stop acting as if the methods and policies of the past will suffice to protect the rivers and streams of Colorado in the future.