PONDS
Throughout Kiawah Island are a series of 122 interconnected stormwater ponds that store water through drainage systems , which are eventually conveyed off the Island . The health of the majority of the ponds is monitored and maintained by the Kiawah Island Community Association ’ s ( KICA ) Lakes Management Department which has monitored water quality since 1987 ( Hill , 2021 ). Currently 26 ponds are tested each week for a variety of parameters , including temperature , conductivity , salinity , depth , pH , and dissolved oxygen . SCDNR is also contracted to seasonally monitor for toxic algae and other phytoplankton as well as to monitor bacteria levels twice a year . At least 21 scientific research studies of these ponds have been published since the first comprehensive review found in the 1975 Environmental Inventory of Kiawah Island . These cover topics such as ecotoxicology , algal blooms , and phytoplankton levels .
Our ponds are home to a wide variety of fish , invertebrates , wading birds and waterfowl , snakes , and alligators and are important to the island ’ s biodiversity and ecological health of Kiawah Island . Possible threats to the ecological health of the ponds include saltwater inundation , stormwater runoff , and eutrophication . The increase in impervious surfaces limits the natural ability of rainwater to percolate into the soil and recharge fresh groundwater . Stormwater that does not percolate into the soil produces runoff that flows through the stormwater pond infrastructure and eventually into marshland .
This runoff also carries soils , pollutants , and organic matter into the water , which can impact water quality . Excess nutrient concentrations in the water from stormwater runoff can lead to algal blooms and other impairments to water quality . Of particular concern is the eutrophication of water bodies caused by excessive levels of nitrogen and phosphorus levels , which contribute to the production of algal blooms that occasionally result in fish kills . Potential annual water quality nutrient loads for nitrogen and phosphorus produced in the upland watersheds can be estimated by analyzing landcover data using stormwater calculations ( VDEQ , 2013 ). Areas with more forest coverage and less impervious surface were observed to provide the least amount of nutrient export into water bodies . Reducing the introduction of nutrients from runoff into ponds prevents the degradation of water quality in ponds .
Ecological Health of Kiawah Island 2022 30