Slippery Rock Watershed Assessment
	WATERSHEDS AND THEIR ASSESSMENT

Introduction to Watersheds

Officially, a watershed is the area of land that drains into a specified body of water. If you find that definition a bit confusing, you are not alone. Try thinking of it this way: choose a body of water you're familiar with, perhaps a local stream. Now think of where the water in the stream comes from. Although there are many ways for water to enter a stream, much of it will enter as run-off from the land. This land is what forms the stream's watershed. Now think of where the stream goes. Does it run into a river? If so, the original stream and its watershed, because they are part of the land draining into the river, are part of the river's watershed. As you can see small watersheds make up larger watersheds, which form even larger watersheds, and so on.

To keep them all straight, watersheds are generally given the name of the body of water the land sends water into. So, the Slippery Rock Creek watershed is the area of land that sends water into Slippery Rock Creek. Because the water from Slippery Rock Creek eventually drains into the Ohio River, the Slippery Rock Creek watershed is a small watershed (known as a sub-watershed) within the Ohio River watershed. The Ohio drains into the Mississippi River, making the Ohio River watershed a sub-watershed of the Mississippi watershed, which drains into the Gulf of Mexico. We could go in the opposite direction as well, and determine what sub-watersheds exist in the Slippery Rock Creek watershed, but I suspect you've had enough. If you are interested in knowing what they are, pull out a map and see what you can discover on your own.

Because water runs downhill, watersheds are defined by natural boundaries. One watershed ends and another begins at the highest point between the two bodies of water. This causes watersheds to cross county, state, and national boundaries.

All known organisms living on the earth require water for survival. Non-living substances found in water that are harmful to living organisms are called pollutants. These pollutants are generally, but not necessarily, chemical. They include things like abandoned mine drainage (AMD, sometimes known as acid mine drainage), excessive nutrients, and excessive siltation/sedimentation. Note the use of "excessive" in the previous sentence. It is not the presence of these substances that causes trouble; it is the presence of too much of them.

Watershed Assessments

Watershed assessments can be thought of like medical check-ups for watersheds. People who are trained in what to look for will examine the watershed to see if it is healthy. If it isn't, they will determine what is making it "sick" and offer suggestions on how to make it healthy again. Just as a doctor can't perform an evaluation on a person without their permission, we cannot and will not force our way onto personal property. In addition, just as a doctor cannot force treatment on a patient, the assessment will not lead to any regulatory action. Suggestions will be given for how to make the watershed healthier, but landowners will choose whether or not to follow them. These suggestions are likely to include things such as building passive treatment systems for AMD and establishing vegetated zones along the stream banks to reduce erosion and sedimentation. These zones are known as "riparian buffers" ("riparian" meaning "along the banks of a river" and "buffer" meaning "a device used as a shield or cushion"). They work because the plants reduce the amounts of pollutant that reach the river by slowing down water running off the land, holding the soil with their roots, and absorbing nutrients that would otherwise end up in the stream.

You might find the following links about watersheds helpful, and there are plenty more out there:
http://www.kishwatershed.com/index.htm -- another watershed assessment in PA
http://dnr.metrokc.gov/wlr/PI/WATERSHD.HTM -- a general introduction to watersheds: King County WA
http://www.dep.state.pa.us/dep/deputate/enved/watershed/watershed.htm -- general information: PA DEP
http://www.greenworks.tv/watershedstv/ -- newsletter type format, lots of information, changes frequently -- definitely worth checking out: Watershed.tv
http://www.pawatersheds.org/index.asp -- the home site for POWR (Pennsylvania Organization for Watersheds and Rivers)
http://www.state.nj.us/dep/watershedmgt/basicinfo2.htm -- lots of information on watersheds including pollution sources and what you can do to improve your watershed: NJ DEP
http://www.brodheadwatershed.org/bwa/7.htm -- many links: Brodhead Watershed Association, Henryville PA
http://www.cleanwater.gov/success/conemaugh.html -- watershed success stories

The following list includes links with more information on AMD and its treatment options.
http://www.dep.state.pa.us/dep/deputate/minres/bamr/amd/science_of_amd.htm -- more technical AMD info. (including the chemical formulas): PA DEP
http://pa.water.usgs.gov/projects/amd/index.html -- information on coal mine drainage in PA: USGS
http://manila_wetland.tripod.com/manila_amd_wetland.htm -- brief intro. to an AMD clean-up project in WV with many links: Heizer-Manila Watershed Organization
http://www.dep.state.pa.us/dep/deputate/minres/reclaimpa/reclaimpahome.htm -- Reclaim PA: PA DEP
http://www.leo.lehigh.edu/envirosci/watershed/riverexp/mine/ -- many links: LEO EnviroSci Inquiry

More links you may find interesting:
http://www.dpiwe.tas.gov.au/inter.nsf/WebPages/RPIO-4YK9Z8?open
http://schools.ceh.ac.uk/advanced/freshpoll/freshpoll1.htm
http://www.gcrio.org/geo/soil.html