Because development has dramatically altered the hydrologic environment’s sustainability, the Milwaukee Metropolitan Sewerage District (MMSD) is encouraging the use of “green” design through stormwater management BMPs. The MMSD asked Graef, Anhalt, Schloemer and Associates, Inc. (GAS) to evaluate and design stormwater management BMPs. The MMSD headquarters in Milwaukee, WI is serving as test site for creative stormwater management solutions. In order to best match needs of the MMSD headquarters site, GAS analyzed configuration and tributary areas of the storm sewer system to determine anticipated flow rates and most feasible BMP installations. Five treatment techniques were selected: constructed wetland treatment, structural stormwater treatment units, drop in catch basin inlet filters, native plantings to facilitate stormwater infiltration, and the use of porous pavement in a designated test area. The MMSD project is serving as an active, operable test site for various types of stormwater management and treatment BMP systems. An added value of the project is that it demonstrates that creative applications of the various BMP systems available can be provided in nearly any setting, even the congested settings of fully developed areas in the urban environment. Through the creative and innovative applications of these BMP measures, it will be possible to “turn back the clock” on stormwater management and water quality, returning our water resources to the level of ustainability they had before the impacts of man’s intensive development.
Sustainability - The ability to sustain or maintain at length without interruption, weakening, or losing power or quality.
The hydrological cycle is a classic example of sustainability. Water is so important to human existence that when scientists study the universe and examine planets, the key features that they look for is evidence of the existence of a water environment. This is an indicator of the potential of humanoid and other biological life as found on earth. Prior to development by man, the hydrological cycle maintained the equilibrium of water, flora, and fauna in an ecologically
balanced environment. Rainfall cleansed the air and the surface of the land and carried nutrients to the root zones of plants and to the soil. Contaminants were removed by the chemical uptake of plants and by electrochemical reaction of soils. Rainfall percolating through the soils was cleansed and recharged the groundwater aquifers.
Evapo-transpiration from the plants and the surface bodies of water recharged the atmosphere to form clouds for future rainfall. Water runoff and watershed drainage, slowed by the heavy plant growth and reduced by infiltration, traveled to rivulets, tributaries, and streams to replenish surface waters. Purified ground water released to springs contributed cold, clean waters to streams and rivers. Excess rainwater runoff led to increased flood stages and seasonal flooding of riverine floodplains. The seasonal fluctuation in waters occupying the floodplain sustained hydrophytic plants, which occupied the floodplain areas. The seasonal availability of shallow, fertile, and protected floodplain spawning areas enabled aquatic and other species spawning and breeding. Flood flows were tolerated due to the adaptability of the flora and fauna through the natural cyclical process. Water continuously sustained the ecological cycle.