A total of 537 water bodies were counted during the City's 1997 inventory. Many of these are used for stormwater treatment. Urban development typically increases runoff due to the added hard surfaces, such as roads and rooftops. For example, the total runoff from a one-acre parking lot is about 16 times that of an undeveloped meadow. Stormwater ponds are treatment ponds designed to intercept and treat a variety of materials, both point and nonpoint sources.
Treatment ponds can also include wetlands where stormwater has been diverted for natural treatment.
Point source pollution comes from a specific point, such as a pipe. Nonpoint source pollution results from improper land management, over-fertilization, erosion and sedimentation. As these materials enter into the stormwater pond, they can accumulate and exert a detrimental effect on the system, resulting in blue-green algae blooms or excess weed growth. In some cases, the water can become toxic to pets if large amounts of the blue-green algae accumulate. City Policy Treatment ponds are designed primarily for water quality treatment, stormwater detention and flood control.