On a 700-acre property at 1001 Olive Branch Rd. in southeastern Durham County, there are plans to build a large residential development (Sierra and Egypt tracts). According to the NRCS soil survey, 95% of the 700-ac does not perc, so the issue for the developers is whether the property can be rezoned to receive city water and sewer. I've been told the rezoning request for the Sierra tract passed the county commissioners 5-0. On Monday, the request goes to city council. After visiting the site and spending several hours with GIS data, there seem to be a number of environmental issues of obvious concern: According to the NRCS, soil suitabilities on the 700-acres include: Dwellings with basements: 98% of the area is classified as "very limited" Dwellings without basements: 96% classified very limited Small commercial buildings: 96% classified very limited Lawns and landscaping: 60% classified very limited, 40% somewhat limited Erosion hazards from roads and trails: 56% classified severe, 38% moderate Soil rutting hazard: 65% classified severe, 33% moderate Playgrounds: 97% classified very limited The main problem with this property is that it is in an area of concentrated White Store soil, a soil with world-class shrink-swell capacity, stickiness, and impermeability. Nearly 60% of the property is underlain by these plastic-clay soils. There are consequences for carelessly developing the southeastern part of Durham County. Much of this land is in the Triassic Basin and thus has many White Store soils. Like the Sierra and Egypt tracts, much of the land is immediately proximate to Falls Lake. Many of the subcatchment streams are already impaired. Due to historic land uses, the creek transports enormous amounts of sediment to the Lake.