Earth – the water planet. All of life on Earth depends on H2O for survival. If you are a saltwater creature, you are in luck because 97% of the Earth’s water is salty. The rest of us must share the remaining 3% of Earth’s water, some of which is trapped in glaciers, deep underground or too polluted to use.

The water that is available for plants, animals and humans comes to us from two main sources – groundwater or surface water.

Groundwater has been accumulating in aquifers for thousands or even millions of years. Groundwater in the Perkiomen Creek watershed can be very variable. Some locations have an abundance of groundwater, other locations have temperamental groundwater supplies that vary greatly with seasonal changes, are susceptible to overuse or are so close to the surface that they limit what can occur at the surface.

Surface water is also abundant throughout the Perkiomen Creek watershed. Most surface water moves quickly through local streams and creeks and eventually becomes part of the salty oceans. Along the way, however, water gets used (and reused) by natural and human communities.

With all this water constantly flowing to the sea, why doesn’t the sea eventually “fill up” and leave us with no fresh water for human or other land uses? The hydrologic cycle, of course! Ocean and surface waters are constantly evaporating, forming clouds and bringing the rain and snow that replenish our water supplies. It is this movement of water through the phases of precipitation, infiltration, evapo-transpiration, evaporation and condensation that ensures that plants, animals and people have enough water to grow and prosper.

Precipitation is also called stormwater and can be characterized as an "essential nuisance". Too much of this good thing can cause serious problems. Creeks and streams have a limited capacity within their banks for stormwater conveyance. So when built communities are located too close to a waterway, a gentle nurturing rain can become a torrent and people and communities can be devastated. In addition to the problems suffered by the human community, raging stormwater can have significant impacts on the natural world causing serious streambank erosion and depositing layers of silt over important aquatic breeding and feeding areas.

Since the mid-1970's, federal and state governments have been refining stormwater management requirements. In 2003, Pennsylvania municipalities with publicly owned and maintained storm sewer systems were required to upgrade stormwater management techniques in their communities. These communities were designated as MS4's or Municipal Separate Storm Sewer Systems. In a nutshell, the overall goal of the MS4 program is to shift common practices away from disposing of stormwater as if it were a waste product and managing it as a valuable resource – which it is.

Under natural conditions, a landscape with lots of trees and undisturbed soils can absorb about 82% of a typical rainfall. Most of that is absorbed by vegetation and returned to the atmosphere through evapo-transpiration. Nearly a quarter of the rainfall slowly makes its way into local aquifers where it replaces the water that has been withdrawn for human uses. About 18%, becomes run-off. The Perkiomen Watershed receives about 43 to 45 inches of rain per year.

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When that same area is developed, the trees are removed and the soils are compacted. In addition, large areas of impervious surfaces are constructed for roads, parking, roofs, etc. Under these conditions, nearly all of the rainfall, 96%, becomes run-off and virtually no water is left to recharge local aquifers. Over time, local aquifers can be reduced significantly enough to affect local wells and water systems.

In the past, stormwater was directed through pipes and man-made basins to the nearest creek or swale. From there, it was a direct trip to the sea where our precious, clean water became part of the salty oceans. Current stormwater management regulations focus on helping precipitation infiltrate into the ground where it will support our natural and human communities.The latest regulations also require MS4 communities to educate their residents about stormwater and the need to increase stormwater infiltration. The Perkiomen Watershed Conservancy has initiated the Perkiomen MS4 Partnership to help communities meet these public education and outreach requirements.

UserFiles/Stormwater/Press Release MS4 Partnership Begins Yr 7.pdf

Additional information will be included at the Perkiomen Watershed Conservancy's website and those of the Perkiomen MS4 Partners. Stay tuned to learn more about how you can help protect drinking water supplies and the natural areas throughout your community.