Protecting our streams key to buffering the impacts of climate change
The most recent report from the International Panel on Climate Change indicates that the greenhouse gases continue to accumulate in the atmosphere at an alarming rate, with concentrations the highest they have been in at least 800,000 years. The thousands of international scientists comprising the panel warn that resulting global warming will severely reduce sea ice and continental ice masses, producing rising sea levels, dramatic changes in ocean alkalinity and modifications of the dominant ocean currents that produce weather.
Last week’s release of the U.S. National Climate Assessment, a peer-reviewed document produced by some 300 highly credentialed U.S. scientists, reports that indeed some of the effects of the greenhouse-gas induced climate shift are no longer avoidable. Indeed, some impacts are already here, manifested in the increased frequency of flooding, wildfires and severe weather events that the nation has experienced in recent years.
In the West, a rapidly changing climate means getting used to more fire, friendlier conditions for invasive species, and most profoundly, erratic water supplies. Scientists agree that even if we reduced all human-produced greenhouse gas emissions today, current concentrations are still high enough to ensure the warming trajectory will continue for decades. And therefore besides tackling the priority task of reducing carbon dioxide and other greenhouse gasses – largely by severely reducing fossil fuel use -- society should also seek ways to buffer the effects of climate disruption that can’t be put back into the bottle.
Though the federal and most state governments have generally failed to significantly deal with carbon emissions, some tools are readily available to reduce the impacts of climate change, especially the long-term trend we are seeing with smaller western snowpacks – this year in Montana notwithstanding – and increased drought and reduced streamflows. The simplest tool is at hand: Doing everything we can to protect and restore the natural function of western watersheds, especially our high basins as well as the natural form and function of streams, floodplains, and wetlands.
Last month the United States Environmental Protection Agency released some common-sense draft rules that will re-instate protective measures for some of the most valuable, but least appreciated waters in the nation – the tens of thousands of stream miles in our mountains, valleys and prairies that are intermittent in nature. The rules clarify that developers and land managers must seek permits and approval under the federal Clean Water Act before they dredge, fill or otherwise damage intermittent streams and wetlands deemed, in legal lexicon, waters of the United States. These rules simply reinstate the permitting landscape that existed before U.S. Supreme Court rulings in 2001 and 2006 created confusion as to what constituted a water meriting protection under the federal Clean Water Act. This legal confusion generally results in no protection. The court rulings also eliminated protection for ecologically important isolated wetlands such as prairie potholes, because a slight majority of justices, rather than evaluating how science informs good law, decided that science was immaterial and so the nation must have bad law. After years of study, the EPA has now crafted protective rules that are consistent with the confusing rulings affecting intermittent streams, though conservation of isolated wetlands is still in limbo.
Because a stream doesn’t run year round, or, it includes reaches that for geological reasons occasionally run dry, doesn’t mean it has no value for downstream communities, agriculture or aquatic species. In Montana, and elsewhere in the Mountain west, intermittent streams are the capillaries that deliver high-elevation snow-melt and spring rains to our rivers. Their beds and banks store water for late season flows, capturing water from winter snows and metering out delivery of critical ground water that helps recharge lower elevation streams. This benefits many Montana communities whose domestic water source is derived from upper elevation watersheds. It benefits irrigators, the majority of whom tap surface or groundwater flows borne in mountains.
Intermittent streams, which comprise more than 60 percent of all stream miles in the nation, are hugely important for sustaining aquatic ecosystems, and critical to most of Montana’s native fish species. Some of Montana’s cutthroat trout populations, including in the Blackfoot River watershed, or in the upper Missouri region, use intermittent streams for spawning. Many prairie species in eastern Montana are 100 percent dependent on stream courses that run dry seasonally. They survive during dry periods in disconnected pools, then migrate during rainy periods.
Investing in protection and restoration of Montana’s large network of intermittent and even ephemeral streams is essential for buffering the impacts of a changing climate. These waters are capital we can ill afford to squander.
This is Bruce Farling of Montana Trout Unlimited. Contact us at www.montanatu.org.