Ohio State University Extension http://ohiowatersheds.osu.edu

Ohio Watershed Network

Ohio State University Extension

The Lake

webpic51.jpgOften times, a stream or creek will flow into a lake. There are three major kinds of "lakes" - lakes, ponds, and reservoirs. Generally, a pond is a body of water no larger than about ten acres in size, whereas a lake can be several hundred or thousands of acres in size - like Lake Erie.

A reservoir is a human-made lake, which may have been built for flood prevention or as a storage basin to provide water for human consumption and recreation.

All of Ohio's lakes have water flowing in and water flowing out, but the water tends to move very slowly once it enters the lake. Because of the higher retention time of water in a lake, sediments and many contaminants in the water tend to settle to the lake bottom.

webpic38.jpgAs the sediments build up, the lake begins to fill in, becoming shallower over time. Activities in the headwaters and middle reaches that cause soil erosion will accelerate the buildup of sediments in the lake, as is happening in many lakes and reservoirs in Ohio. Many of these lakes would fill in completely over a short time, being replaced by a wetland or meandering stream, if the sediments weren't removed from time to time through a costly process called dredging.

Lakes are vulnerable to contamination because of what happens both in and around them. Development of the lakeshore can create pollution problems as fertilizers from lawns and sewage from septic tanks wash or seep into the lake. Recreational activities like boating can also add fuel, oil, and other toxic chemicals to the water. Many lakeside residents are coming together to encourage the adoption of best management practices to protect the lake's ecological integrity.

Now, on let's move on to the Wetlands!