The community has recently become increasingly concerned about flooding and standing water , a result of increased runoff from impervious surfaces and the lack of a significant downhill gradient to move surface runoff more efficiently . Reducing the amount of standing water is a high priority of Kiawah Island in terms of flood mitigation .
The overall resilience of the maritime forest is influenced by the degree of environmental stress placed on the system and its ability to properly function and recover when damaged .
MARITIME FOREST HYDROLOGY
The subsurface groundwater aquifer is influenced by the local weather system and ecosystem processes ( Callahan et . al , 2017 ). On Kiawah Island , the surface of the subsurface aquifer is generally found within 2-4 feet beneath the soil surface ( Moulton II , 2021 ) and can have depths of up to 33 feet ( Moslow , 1980 ). At the base of the aquifer is a confining layer of marine clayey soils , called the Parker ’ s Ferry Formation , which is a relic of ancient marsh sediments . These clayey soils impede the ability of subsurface groundwater from interacting with deeper aquifers .
The island is dominantly covered in marshlands with variations in upland soil types . The upland soils are within category A , B , C / D , or A / D hydrologic groups , generally characterized as poorly drained , loamy fine sands . Group A / D soils experience different runoff potentials due to soil saturation , with unsaturated soils causing low runoff ( high infiltration ) and saturated soils causing high runoff values ( low infiltration ). On Kiawah Island , the built environment typically contains soils within the A / D hydrological group . A summary of soils found on Kiawah Island can be found in Table 1 and Map 1 .
Table 1 . Description of soil types found on Kiawah Island
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NATURE-BASED SOLUTIONS MANUAL FOR KIAWAH ISLAND