Do you own property that fronts a stream or river? If so, consider maintaining some plants and vegetation around the edges of your stream (a "riparian buffer"). Having native trees and shrubs around streams is very important for maintaining clean waterways that are able to support fish and other animals. They help filter pollutants before they can reach the stream, they provide shade that can stabilize water temperature, they decrease the severity of flooding, they strengthen stream banks to protect from erosion, and they provide habitats for land and aquatic wildlife.
If you currently just have grass on your streambanks, consider planting native trees, shrubs, or herb-like plants, and avoid mowing and clearing within 30-50 feet of the streambank (the more of a buffer the better). Also look out for exotic invasive plants since some of these can alter streamflow and smother out the surrounding vegetation.
(advice borrowed from the Jackson Co. Sustainability Council)
“Water is the driving force of all nature.” – Leonardo Da Vinci
“You, O Lord, care for the land and water it; you enrich it abundantly.” – Psalm 65:9