What is a watershed?  It is a land area that channels rainfall and snowmelt to creeks, streams, and rivers, and eventually to outflow points such as reservoirs, bays, and the ocean. 

Watersheds are like Russian nesting dolls: little watersheds fit inside larger watersheds. 

Pleasant and Pero Lakes were formed thousands of years ago by glaciers. Pleasant Lake's main inputs of water are now from groundwater seepage and rainfall.

The orange shape represents the extent of Pleasant Lake's watershed. Any rain that falls in that area or runoff that flows over the ground ends up in the lake.

The red point marker indicates the only outflow from the lake. This overflow provides vital water for the special forested wetland habitat that connects Pleasant and Pero Lakes.

Pero Lake's watershed covers a much larger area than Pleasant Lake's watershed. 

While Pleasant Lake's watershed area to lake surface area ratio (WA:LA) is approximately 8, Pero Lake's ratio is around 180. 

This means that Pero Lake's water quality is not only affected by Pleasant Lake's water, but it is also impacted by all of the activity occurring within the dark orange shape.

Pleasant and Pero Lake's watersheds are both contained within the Holloway Reservoir watershed (turquoise outlined area).

The Environmental Protection Agency's (EPA)  How's My Waterway tool reveals that the water quality in the Holloway Reservoir and many surrounding streams is impaired. In this case, the primary known issues are polychlorinated biphenyls (PCBs) and per- and polyfluoroalkyl substances (PFAS).

Without the preservation of undeveloped habitat, like the floodplain and forest habitat preserved within the Davison Hogbacks, water quality would worsen.

The next stop for our lakes' water is the Kearsley Creek watershed (blue outlined area).

This watershed area includes Flint, Davison, Ortonville, Otisville, Columbiaville, and Goodrich. 

This watershed (light green outlined area) contains all the lakes, streams, and land area that drain into the Flint River. It receives input from 7 counties and approximately 1,358 square miles.

The Flint River Watershed Coalition works to protect the quality of our water by providing monitoring, community engagement, and other resources.

We've made it to Lake Huron!

Welcome to the Saginaw Bay Watershed: a very special watershed. It is the largest contiguous freshwater coastal wetland system in the United States.

Twenty miles inland from Lake Huron, the water from the Flint, Shiawassee, Tittabawassee, and Cass Rivers all meet at Shiawassee National Wildlife Refuge to form the Saginaw River. 

This refuge provides vital ecosystem services to help our water stay clean and clear. Without the forests, wetlands, and floodplains preserved in this area, the runoff from agriculture, housing, and urban areas would not be filtered. 

The Saginaw Bay Watershed Initiative Network works to protect these invaluable resources.