Whether man-made or natural, changes in the watershed changes our lives. It’s all connected. Nature’s changes can be as quiet as branches building up behind a fallen log that changed the path of a stream. Or they can be as dramatic as a winter flood. Our actions, too, can be subtle or dramatic, like when we cut our forests, clear land, lay concrete and asphalt, and build houses. These changes mean the water cycle will work differently.
The word watershed means “a parting” or “a shedding of waters.” But a watershed is a gathering place also. It is a place where hills and plains and peoples’ lives are connected by falling rain and flowing water.
A watershed is measured by the hilltops and ridges that are its boundaries. It is shaped by the hills, valleys and plains that are its landscape and is tempered by the forests, fields, lakes and marshes that are habitats for its creatures. Most of us know a watershed through the streams and rivers that connect forest with farm, farm with city, city with San Elijo Lagoon and the Pacific Ocean. We each change the watershed day by day, bit by bit, as we go about the business of our daily lives.
In a watershed, rain, rivers, lakes, wetlands, and even our drinking water, are all part of an intricate cycle. When rain falls onto land, some soaks into the earth, some runs off into streams, and some evaporates before it even reaches the ground. The water that soaks into the ground becomes part of the groundwater and feeds the streams and wetlands and supplies some of our drinking water. Surface runoff forms streams that flow into rivers that eventually empty into the San Elijo Lagoon and the Pacific Ocean. Rivers are a sign that the cycle is working. Water returns to the oceans where it evaporates, forms clouds and falls as rain once again.
As land is developed, rain striking the ground has fewer places to soak in gradually. Runoff becomes faster and more violent, causing erosion and flooding. Water quality deteriorates as contaminated water drains from farms and cities. Pesticides, animal waste, oil and heavy metals end up in our groundwater, streams, rivers, and, eventually, the San Elijo Lagoon and the ocean. Animal habitats are damaged along the way.
The watershed, the water cycle and our lives are all connected. Any action, anywhere, affects the land, the water, and ultimately, us.
Remember: We all live downstream!
U.S. Environmental Protection Agency's Watershed Page