In Norman, Okla., the Trailwoods community is demonstrating the benefits of green infrastructure when compared side-by-side with traditional stormwater management techniques. The neighborhood, developed by Ideal Homes, includes 17 lots constructed with curb and gutter and downspout-to-driveway conveyance as well as two stormwater basins. Another 17 lots are designed with rain gardens, rain barrels, and downspout diversions. Construction of homes began in 2011. Green infrastructure was installed and monitoring equipment fully operational in October 2013.
The University of Oklahoma conducted the monitoring. Researchers found that, compared to the conventional side, Trailwoods green infrastructure has reduced nitrogen by an additional 30%, suspended sediment by 32%, and phosphorus by 152%, according to a recent article in the Bay Journal.
In sum, Trailwoods includes 366 m2 (3940 ft2) of rain garden installed at a cost of $312 per square meter ($29 per square foot), and the rain barrels cost $35 each. The neighborhood also includes an 11-m2 (120 ft2) area of porous paving installed at $65 per square meter ($6 per square foot).
Though the green homes cost more to construct and buy, the green side of the development has fewer landscape needs, lower energy bills, and is helping to improve the water quality of Oklahoma’s Lake Thunderbird.
The Oklahoma Conservation Commission, City of Norman, and two consulting firms, CH Guernsey and SMC Engineering are also involved in the project.