What happens to the water when it rains in Jamestown?

This isn’t something that we usually think about. However, it is very important to understand the natural rainwater cycle in order to understand the effect development has on runoff and the importance of stormwater management.

The Natural Rainwater Cycle (Depicted in the diagram below):

In a forest, meadow or other natural area rain is usually:

• Taken up by plants
• Evaporates back into the atmosphere
• Flows into the nearby rivers and streams (surface runoff) and Is absorbed by the ground, recharging our aquifers (infiltration into groundwater).

The Effect of Development on the Rain Water Cycle:

Instead of rain water going into the ground as it does in a forest, in developed areas much of the rain falls on impervious surfaces (sidewalks, pavement, roofs) and then flows directly into nearby rivers, streams, ponds, wetlands and the Bay. When rainwater is not absorbed by the ground but flows over the surface it is called “runoff”. It is part of the natural hydrologic cycle (rainwater cycle) to have some runoff, but as more of the landscape becomes covered by impervious surfaces a greater amount of water turns into runoff.

We see runoff flowing down the road toward stormdrains or coming off a roof into a gutter when it rains. Runoff can pick up contaminates while traveling over impervious surfaces, this is why stormwater management is important, especially in Jamestown where we rely on groundwater recharge.

Click here for a summary of the EPA Phase II Stormwater Program

Free viewers are required for some of the attached documents.
They can be downloaded by clicking on the icons below.

Acrobat Reader Windows Media Player Word Viewer Excel Viewer PowerPoint Viewer