Set Up Camp on an Established Clearing
Get as close to the water as you can if you plan on doing some fishing, but remember to set up camp only on an established clearing near the water. Moreover, if you notice numerous animal prints at the water's edge, you have most likely stumbled on a regular wildlife access point to the water. This is not a good place to make camp.
Do not remove vegetation to make room for your tent and fire pit or dig a trench close to the water. Also, stay sufficiently clear of the water's edge to prevent any alteration of the coastline.
Remember also that staying close to the water's edge will put you in close proximity to swarms of mosquitoes. Pack personal insect repellant but try to avoid the swarms as much as possible.
Establish Human Waste Containment
Dig a sewage hole at least 200 feet away from the water's edge. This prevents the sewage from contaminating the water. Make sure that the hole is deep enough---about 10 inches deep---to ensure that even during a rain the sewage will not spill over into the water. Use biodegradable toilet paper, such as may be found in recreational vehicle supply stores.
If you bring a pet along, it is vital to also clean up after the animal and then dispose of the feces in the waste containment hole you dig.
Set Up a Gray Water Site
Do not wash dishes in the lake or stream. Instead, establish a clearing away from the water where you may wash your dishes and rinse off any items that require cleaning during your stay. Minimize the water used, and only rely on environmentally friendly dishwashing liquids.
Strain out solids---such as pieces of caught fish and other foods---and dispose of them as trash. When finished, dump the gray water away from the water's edge.
Return Your Campsite to an Unspoiled Appearance
Carry a little rake with you to loosen matted down vegetation and give it a chance to stand up again rather than remain weighted down. If you gathered rocks to build your fire pit, return them to their places of origin. Cold ashes may be disbursed over a wide area away from the water's edge.
Teach your children, if they built forts or other structures at the water's edge, to return that area back to its natural appearance.