In order to protect itself from possible increased flood damage, the city of Raleigh passed a resolution (Appendix 8) as part of the Final Environmental Impact Statement for the Crabtree Creek, Wake County, North Carolina Interceptor Sewer Project in 6/18/1976 to establish a policy regarding the expansion of city facilities. The resolution states
“… the City of Raleigh joins the County of Wake in taking a position of not encouraging development of land which will necessarily result in greater liquid runoff, soil erosion and sedimentation until adequate devices have been install to reduce those adverse effects of land development.”
Estimates of Annual Average Flood Damages in the Crabtree Valley Mall Area in 1976 were estimated in the EIS to be $276,000 without flood control structures pre-expansion of the Crabtree Sewer Interceptor, and $560,000 when the watershed was 80% developed without flood control structures after the Crabtree Sewer Intercepter expansion. Several, but not all of the flood control structures were built including Lake Crabtree, which is a high-hazard dam. I don’t know the actual annual flood damages incurred in the past 40 years, but they are in the millions of dollars, and these damages and harms strike those who are the least able to recover.
Crabtree Valley Mall has installed flood gates, and issues broadcast alerts to shoppers but when Crabtree Creek raises 10 feet or more, this puts property and lives at risk.
Recently, Raleigh asked people to evacuate their homes for Hurricane Florence, more than 26,500 people were at risk due to living in a floodplain. Raleigh’s population is just under 500,000 according to this N&O article.
“If we get the type of rain that is being predicted with this storm, those areas will flood,” said Blair Hinkle, Raleigh’s assistant engineering services director. “I know there are areas that have swift-water rescues and those who had to be rescued in their homes. If that has ever happened before in an area where you live, we encourage you to seek higher ground.”
The city of Raleigh has a map of flood-prone areas on its website, and the state has created a flood-risk Information system where people can plug in their address to see their flooding risk.
The flooding along Crabtree Creek at the Crabtree Valley Mall area has gotten worse over time. The development and resulting increase in impervious surface in the Crabtree Creek Watershed upstream is responsible for this. The RDU Airport Authority should not pursue development of the Odd Fellows tract by leasing it to the Wake Stone Corportation, as per the City of Raleigh and Wake County Policy cited above.
If Wake Stone Corporation is allowed to lease the land from the RDU Airport Authority and expand their quarry, then the quarry would be adjacent to the stream course on both sides of Crabtree Creek and downstream from a high hazard dam. They will also be using explosives to mine the rock that is situated near the Jonesboro Fault line. The fault line also separates the type of rocks and soils that are present within the Crabtree Watershed, with soils that permit less stormwater infiltration to the west of the fault line, and more stormwater infiltration possible for the soils to the east of the fault line. The Odd Fellows Tract is currently forested, and is helping to absorb stormwater. Converting this land to a stone quarry will increase runoff to Crabtree Creek.
The combination of environmental risks and hazards of flooding, additional sedimentation and erosion and additional discharge to Crabtree Creek due to a potential development of the Odd Fellows Tract by expanding the Wake Stone Quarry should require a full environmental impact study and public hearings prior to leasing this land for development.
The Wake County Board of Commissioners, Town of Cary, RDU Airport Authority, Town of Morrisville, City of Raleigh also need to revisit their current floodplain ordinances, soil erosion and sedimentation ordinances, and stormwater best management practices to capture and infiltrate rainwater and preserve and expand forested areas. Save #RDUForest!
