HELP!!! I THINK MY WATERSHED BROKE!

A watershed is the region of land within which rain and surface water flows into a common drainage.  We live in the Chesapeake Bay Watershed, a large and well-studied area that covers 64,000 km² and includes parts of Delaware, Maryland, New York, Pennsylvania, Virginia, and West Virginia.  Currently, 17 million people and (185 million livestock) live here.  And thanks to urbanization and land use change needed to support all of us, the watershed has begun to break down.

Over the last few centuries, we have significantly changed the natural state of the land in this region.  Areas that were once forested are now farmland or are filled with roads, houses and parking lots.  All of that construction and farming brings with it substantial waste in the form of sediment, pollutants, and an overabundance of nutrients like nitrogen and phosphorus.  So where does a lot of it go?  You guessed it—our rivers, streams, and, eventually, the Bay.  Most of our urban waterways are not places I want to go for a swim or even walk next to!

In addition to the typical pollutants we tend to associate with populated areas—industrial chemicals, heavy metals, vehicle exhaust—we also use a lot of road salt in the winter in this region.  Gotta get to work on a snowy day, right?  You don’t want to slip and fall on an icy sidewalk either.  If you never thought about where the salt goes once everything melts…yikes!  The figure below shows what has happened to salt (chloride in this graphic) in Baltimore waterways recently. 

More salt accumulates in urban areas, and it has reached levels that are damaging to plants and animals. Salt has even impacted the drinking water in the Baltimore area and could be a few decades away from having a drinking water reservoir that, from a chemistry perspective, begins to resemble ocean water.  And as much as you may like to put salt on things, you can’t drink from the ocean.

So what are we doing to fix everything that is broken in Chesapeake Bay Watershed? A LOT!  Policies are in place to reduce nutrient loads entering our rivers from farms and cities.  Education efforts from elementary schools to town hall meetings teach people about these problems and some of the solutions.  Stormwater management is considered on any new building site. And the scientific community is part of a large, concerted effort to work toward solutions that will benefit future generations.

My personal interest is in what we can do to help out urban streams.  Many streams are candidates for “restoration” in order to stabilize their banks to reduce erosion, add engineered structures to slow down the water, or reconnect streams with their floodplains through the creation of wetlands.  These are all designed to be functional and aesthetically pleasing,   But restorations can be expensive, so we have to consider a lot of questions to determine if we are spending our dollars wisely:

·         Are restorations successfully changing the chemistry of the water?

·         How much improvement can we expect?

·         How long will it take?

·         What are the best practices?

·         Where are they most effective?

We take part in long-term monitoring and frequent sampling of water upstream and downstream of where a restoration strategy has been put it in place.  We analyze the water chemistry in a lab to measure any seasonal differences, changes between normal flow conditions and storm events, and any identify entry of pollutants and nutrients from sources we can’t see.  You might have been thinking that a watershed is just affected by what happens at the surface. We wish it was so simple!  We have to consider a complicated, dynamic system underground and all of the changes that occur through time.  This is especially true in urban areas.  All of the broken, leaky pipes and sewer systems are now part of the watershed and are potential problem areas.  Even if you don't live in a city, remember that everything is connected.

We have a long way to go to identify how much damage has been done and how we can make improvements.  This is not just a regional or local issue.  It is a global consideration on the level of climate change.  Water is a necessity for life.  People aren’t moving away from our nation’s waterways anytime soon, so we have to learn how to coexist and create sustainable communities.  Help solve the problems locally and surf your watershed to find out about efforts in your own area. A broken watershed can’t fix itself.