Marine Biochemists - Watershed Management Page

A watershed or drainage basin is basically defined as the total area of land that drains toward a given lake or pond. Run-off can carry with it materials detrimental to the longevity of a lake or pond. When problems from a surrounding watershed begin is hard to tell as many lakes have histories that are not documented very well, but current practices within a given watershed can be modified in order to slow down the advanced aging of a lake or pond (a process known as advanced eutrophication).

Advanced eutrophication is primarily caused by non-point source pollution. This includes agricultural run-off from operating farms and excavated farm lands (new residential developments), run-off from lawn fertilizer use, livestock waste run-off, run-off from pet wastes, leaking septic systems, water fowl droppings, leaf litter, grass clippings, etc. Humans are the main cause of non-point source pollution. Rainfall can wash in large amounts of non-point source pollution into many area lakes and ponds. Areas that normally are not a contributing factor to the non-point source pollution problem can quickly become pollution sources. Current human activities within a watershed can be modified , however, to reduce the impact of human influence. These modifications include the following:

Leaving a buffer zone of uncut vegetation around the shoreline to aid in binding up nutrients that would otherwise run into a body of water. The size of this buffer zone is dependent on the slope of the area. Typically, buffer zones are ten to fifteen feet in width, but should be larger for steeply sloping areas.
Monitoring fertilizer use in the watershed. This includes not fertilizing around a body of water or in areas that would provide run-off into a body of water should rainfall occur. If fertilizers have to be used in potential run-off areas, a low Phosphorus or no Phosphorus fertilizer should be used. The majority of ponds and lakes that we find to have declining water quality are directly affected by irresponsible fertilizer use. The correlation that what makes grass green will make ponds and lakes green is direct and all too accurate.
Monitoring lawn care practices. This includes eliminating grass clippings from entering a body of water. Grass clippings are high in Nitrogen which is the secondary limiting nutrient for aquatic growth next to Phosphorus. These should not only be kept out of a water body directly, but also out of sewers and ditches that drain into water bodies. Changing cutting practices may be as simple as facing the mower outlet for the clippings the other direction and not cutting up to the edge of the lake (though this gives a manicured look, it is environmentally unsound).
Monitoring leaf litter and other organic debris. There is no way to eliminate leaf litter and debris from entering a body of water, but large amounts of leaf litter and rich organic matter from lawns, gardens, pet wastes and/or flower beds can add a tremendous amount of nutrients to an aquatic system and should be kept out of lakes, ponds and potential run-off areas.
Monitoring miscellaneous sources of Phosphorus. Quite a few of detergents and cleaners are Phosphorus based and can detrimentally affect water bodies. The use of environmentally sound detergents and cleaners in outside areas that may feed into water bodies including areas where vehicles are cleaned or maintained will aid in the non-point source pollution problem.
Discouraging waterfowl presence. This is easier said than done. Waterfowl can add a tremendous amount of nutrients to a body of water. The presence of geese is always going to be a constant factor at many lakes and ponds, but there are a few things that may help in reducing their numbers. Never feed the geese or do anything that might influence their normal migratory patterns. This may sound simple, but there will always be someone who is tempted to provide for the migrating flocks. Not only does this change the natural behavior of the geese, but may influence their normal migratory course. The installation of goose fencing is recommended to keep the geese off of the cut grass areas. We have found that adequate goose fencing irritates the geese by preventing their easy access of grass areas from the water. The best type of fencing that we have seen is a very simple design consisting of stakes placed approximately 30 feet apart and two tiers of taut line (chalk line or similar twine) run between them. The bottom line should be approximately 4 to 5 inches off the ground with the second line approximately 5 inches about that. The fencing should be placed right on the shore/water interface and should not allow access from around the ends if possible. Heavily vegetated shores will be difficult to fence, but we have noticed that geese prefer the short vegetation for grazing and the ease of predator detection. We have also noticed that dogs are a fairly good deterrent, but they are sometimes not always available especially during the night hours.

Water is an important resource and should be respected as such. The beginning of lake and pond improvement almost always starts with the individual property owner in a given watershed. Once a conciousness of the effects of non-point source pollution becomes realized, only then can real progress be made toward improving water quality. See also Water Quality Analysis Services and Aquatic Consulting.