Watershed Management

What is a watershed?

A watershed encompasses all the areas that contribute water to a water body. For example, the Long Island Sound includes the northern part of Long Island, as well as portions of Westchester County, Connecticut, Massachusetts, New Hampshire and Vermont.

What are the harmful impacts of urbanization on water quality?

Listed are some of the potential impacts:
Massive "pulses" of sediment from construction sites during and after storms. Increased wash off of pollutants (trash and debris, trace metals and nutrients, toxins, gas and oil) Increased stream temperatures Increased algal growth in surface waters from excessive lawn fertilizers.

How can harmful impacts on water quality be reduced?

Best management practices (BMP) is a phrase which means the best available techniques to reduce harmful environmental impacts. BMPs for urban watershed management are typically storage tanks or other devices that temporarily store and/or treat urban runoff to reduce flooding, lower stormwater temperatures, or remove pollutants. BMPs also include natural practices such as grass filter strips that serve to stabilize the soil, filter pollutants and minimize flooding.

What can urban best management practices do for water quality?

Here are some examples of what BMPs can do:
Help reduce the impacts of development. Used alone, however, they are not sufficient to prevent water quality degradation; they should be used together with many other efforts. Prevent flooding by storing stormwater runoff and gradually releasing it downstream. Reduce pollutant concentrations by storing sediment and absorbing nutrients before they reach surface waters such as the Croton Reservoir, Hudson River and Long Island Sound.

What are the different kinds of best management practices?
Here are three general categories of recommended Best Management Practices for water quality treatment:
Infiltration - Infiltration BMP's retain stormwater runoff and allow it to seep into the soil, recharging local groundwater levels, reducing runoff volumes and filtering pollutants. Retention - Retention basins are permanent pools of water that allow for storage of floodwaters, groundwater recharge, streambank erosion control and settling of sediments and attached pollutants. Extended Detention - Extended detention basins temporarily detain stormwater runoff. By detaining stormwater for a length of time, pollutants settle out of the water column and downstream areas receive flood protection. These basins normally remain dry between storms and do not have a permanent pool of water.

Here are two general categories of BMPS for soil stabilization and sediment control:
Erosion Control - A variety of BMPs may be used to stabilize the soil and prevent soil particles from washing off the surface by wind and water. Erosion control BMPs should be the primary weapons in erosion and sediment control plans and programs. Sediment Control - If erosion cannot be prevented, sediment control structures and practices are available to help retain sediment on site and prevent it from washing into streams, wetlands, lakes and ponds. In our area, black silt fences are installed prior to construction to keep sediment on the site and prevent it from entering our waterways.

Conclusion

Planners, developers and engineers can apply BMP designs to protect water quality and enhance the economic value of your home. Creative planning and design of BMPs can improve their function and provide other benefits, such as habitat for fish, birds, and mammals. BMPs can also enhance the aesthetics of new development and reduce maintenance of catch basins and other infrastructure, such as your water and sewer utilities. Most importantly, BMPs, along with other measures, are essential to protect water quality.