The Sommet at Big Bend is an 11 acre development for custom Villa homes. Miracle Design Build, a United States Green Building Council member firm owned by Architect Jim Holtzman, had heard about the rain garden concept and wanted to apply that style of stormwater conservation to this development.



Controlling the time of concentration for post development stormwater runoff on this steeply sloped site with rocky clay soils was the project design challenge. The solution was to imitate predevelopment hydrology by delaying runoff and spreading it over the greatest surface area possible, thereby allowing infiltration, lower runoff rates and delayed time of concentration.


The system included twenty-eight small, interconnected micro-detention basins throughout the development along the paths of natural drainage. The basins are connected with underground sand drains and overflow pipes. A series of small waterfalls, pools and dry stream channels facilitated overland flow and enhanced site aesthetics. The system is designed to retain water for no more than 48 hours. The plant pallet for each basin includes native flowering wet prairie and wet mesic prairie plants. The prairie plants maximize infiltration and evapotranspiration to improve site hydrology while also providing desirable wildlife habitat and a pleasing landscape.



Enclosed roadway drainage pipes and curb inlets, typical for this

type of development, were eliminated from the design. Instead, stormwater flows through the series of micro-detention basins. The result is a developed site that is hydrologically functional and beautifully landscaped.