Urban Rivers: Managing Clean Water In The City


USGS

I’ll never forget the moment I watched, astonished, a tall man nonchalantly wad up his burger wrapper, step into the street, and toss it directly into the storm drain that led to the Chattahoochee River. How could he not know that streams in our cities are often right beneath us, hidden and buried away, but still leading to our creeks and eventually our rivers?

It was a moment that crystalized for me the vast divide between the clean water we depend on every day and the reality of people’s actions and our land use patterns, intentional or not, that threaten our clean water in different ways. Streams and rivers are everywhere, and yet in our cities and suburbs, urban rivers are often hidden from sight, polluted or degraded.

The U.S. Geological Survey’s (USGS) National Water Quality Assessment program just released a study on the impact of urban development on stream ecosystems across the U.S. Some of the findings include:

  • Urban development changes stream hydrology – Increasing parking lots, roads, rooftops, and other “impervious” surfaces leads to rapid runoff that increases the amount of water reaching a stream in a short time. More water in the stream channel moving at high speeds not only increases erosion, but also prevents infiltration of water into the soil that helps recharge streams and water supplies;
  • Stream habitat is degraded in urban areas – In addition to changes in hydrology that can reduce stream habitat, streams in cities are often straightened or buried which alters what can survive in the stream. Using aquatic insects as the “canary in the coal mine,” the study showed that adverse impacts to aquatic life start at even very low levels of development;
  • Contaminants increase – Urban streams are faced with a variety of contaminants including insecticides, nutrients and polycyclic aromatic hydrocarbons (PAH).

We just celebrated the 40th Anniversary of the Clean Water Act, one of our landmark public health and environmental laws that has improved water quality nationwide. While celebrating, we also examined what’s still left to achieve – one area of widespread agreement is the law’s failures to control polluted stormwater runoff from developed and developing areas.

Fortunately, we’ve learned much more about how to move toward clean water in cities – scientific understanding and practice has evolved – providing important new information to integrate into our water management policies. For example, the USGS report found that there’s always a potential for biological recovery in urban streams, no matter how degraded they are.

Almost 80% of all Americans now live in urban areas, reflecting the need for access to clean and safe streams, but also presenting an amazing opportunity to reconnect people with their hometown rivers while creating more livable communities.  It’s time to explore the impacts of cities on clean water, and work toward clean and reliable water for our human and natural communities who dwell together in the city.