Why Watersheds?
Peter August, Professor
Department of Natural Resources Science
Peter August is the director of the URI Environmental Data Center.
He earned a BS in biology from the University of San Diego, an MS in biology
from Texas Tech University, and a PhD in biology from Boston University. His
research interests include mammalogy, landscape ecology, conservation biology,
and Geographic Information Systems (GIS). He teaches applied ecology and environmental
applications of GIS.
Awatershed is an area of land that
drains water, sediment, and dissolved materials to a stream, pond, or estuary.
Watersheds are delimited by ridgelines or elevation contours that form drainage
basins. Watersheds are, therefore, functional units of geography that are defined
by the flow of water. Rain that ultimately reaches a stream or pond passes through
the varied land uses within a drainage basin. The relationship between land
cover types and water quality is a complex one. Some land uses are sources of
pollutants to the water (e.g., road surfaces, septic systems in dense residential
areas), whereas other land covers are sinks and can remove pollutants from water
flowing through them (e.g., vegetation bordering rivers or streams). In Rhode
Island, the quality of coastal ecosystems ultimately depends on land uses that
characterize our terrestrial landscapes well away from the shore. Given the
intimate relationship between land use and water quality, environmental scientists
now know that drainage basins are critically important regions. These areas
provide the sources and sinks of pollutants. Indeed, the concept of watershed
management is the focus of many local and national environmental protection
programs and policies.
So, why the interest in watersheds? Historically,
most of our environmental management activities were based on the jurisdictional
limits of participating institutions including towns, counties, and states.
Although logical from a legal and budgetary perspective, this geographic apportioning
of the landscape has no connection to ecological or environmental processes.
Watersheds, on the other hand, make sense for water quality management and represent
the geographic unit of hydrological processes. However, they present a political
and funding challenge to decisionmakers. For example,
most of the drainage basin for Narragansett Bay is in Massachusetts; thus, management
of the environmental condition of the Bay is a matter of managing land use and
point sources of pollution in our neighboring state. The U.S. Environmental
Protection Agency has adopted a strong approach to watershed resource management
and is playing a central role to ensure that different jurisdictional authorities
talk and work together.
Watersheds are not the only viable geographic
units of environmental analysis. Whereas the fate of rain and many pollutants
conform to watershed boundaries, plants, animals, and airborne pollutants do
not. Airsheds (for atmospheric pollutants), ecosystems and landscapes (for plants
and animals), and viewsheds (the view from any given point) are all ways to
look at and manage our environment. They represent the geographic units used
by conservation biologists, landscape planners, and air pollution scientists.
In this issue of Maritimes, we have assembled
a team of local experts to describe why watersheds are interesting and important
to land management in Rhode Island. Art Gold and Pete Groffman provide an overview
of some of the more exciting scientific issues in watershed science. Ray Wright
and Dan Urish---environmental detectives---describe how they systematically
determine the exact location of sources of pollution within drainage basins.
Steve Swallow shows us that watersheds can form the basis of economic assessment
of conservation and development opportunities. Meg Kerr, Patricia Hickey, and
Lorraine Joubert make important points that effective watershed management is
not just a scientific process but has social and political implications. Without
the support of stakeholders and land management officials, proper stewardship
is less likely to occur. To know how effective our management programs are,
our water resources must be consistently monitored. Linda Green summarizes how
the Watershed Watch program has mobilized citizen volunteers to keep tabs on
the quality of our ponds and streams. Last, Grover Fugate, and Richard Ribb,
and Tom Ardito discuss how their agencies have incorporated watershed science
into their resource protection initiatives.