This project was proposed to construct an 18-hole championship golf course on approximately 250 acres. The vast majority of that 250 acres exists within the 100-year floodplain of the Mill Creek and White Clay Creek. The floodplain has been designated zone AE with floodway on the Federal Emergency Management Agency (FEMA) – Flood Insurance Rate Maps. Due to the designated floodway, a Conditional Letter of Map Revision (CLOMR) was required by FEMA prior to any land disturbing activity within the floodway being permitted.
In order to fulfill the requirements of the CLOMR application, aerial topography of the entire 750 acre property was shot and field crews collected stream cross-section topography. A pre-development and post-development hydrologic analysis of the 4.7 square mile subwatershed that contains the property was performed. Pre-development and post-development hydraulic models of the 3.25 miles of floodplain that exist on-site were created using HEC-RAS. These models were used to assist the golf course architect with grading design to ensure that the proposed construction of the golf course would have no adverse impact on the floodplain.