Our Approach
Straughan helped NASA Goddard Space Flight Center (GSFC) prepare for the anticipated new stormwater NPDES MS4 permit that will require them to provide treatment for 20% of the existing untreated impervious area. Straughan looked at GSFC’s current stormwater ponds and the last twelve years of development to create a plan to meet the permit requirement and to determine how to meet the restoration requirement in the most cost-effective way using environmental site design practices and retrofitting existing stormwater management ponds.
Straughan used GIS data and aerial photographs to determine the impervious area on campus in 2002. Straughan also inspected the existing stormwater management ponds to determine if they met today’s standards for treatment credit. MDE released new guidelines on meeting MS4 TMDL requirements in the middle of the study, requiring Straughan to change the evaluation criteria. Straughan then used current GIS data to determine the current impervious area on campus. Straughan evaluated 13 additional stormwater management facilities constructed since 2002, compared the 2002 impervious area to the current untreated area to calculate the area requiring treatment.
Straughan performed an intensive desktop and field study of the campus to identify locations for environmental site design and urban BMPs. Straughan strategically located 97 potential ESD/LID practices including micro bioretention, treatment swales, and underground sandfilters to avoid conflicts with GSFC’s built assets. Straughan also suggested MDE- approved alternate BMPs, including stream restoration, reforestation, and regenerative step pool stormwater conveyances for flexibility.
