The Woodlands Neighborhood Green Initiative Infrastructure

The Woodlands is a historic neighborhood in Hinsdale, with original homes constructed in the early to middle 20th century. The neighborhood has a long history of stormwater management issues. The project area had poorly drained roads, and flooding extended well beyond the right-of-way onto private property, resulting in damage to homes and personal property. Roads became impassable during and sometimes long after significant rainfall events. One goal of the Village was to maximize the use of “green initiatives.” The Village hired HR Green to complete the survey, design, bid document, permitting, and construction observation services for Phase I, II, and III of the Woodlands Infrastructure Project.

Using an XP-SWMM computer model, HR Green evaluated a proposed stormwater system using a combination of permeable pavers, bio-swales, rain gardens, underground storage, and storm sewer pipes. The underlying soils were predominantly clay but using soil amendments and strategically placed underground storage in conjunction with green initiatives on the surface, the peak runoff rate was reduced by almost 50% for up to and including the 50-year design storm. This allowed utilizing smaller storm sewers throughout the neighborhood, reducing costs and constructibility challenges. Both infiltration and pipe conveyance was modeled to determine the extent of protection provided and to prevent surcharging. The Woodlands Neighborhood Green Initiative provides an improved stormwater management system comprised of green initiative design concepts, new water mains throughout the neighborhood, lined sanitary sewers, and newly reconstructed roadways.

The subdivision included mature trees within the project area. One of the project’s challenges was constructing the required improvements while minimizing tree impacts. The preferred design using both green and gray infrastructure and smaller diameter storm sewers helped minimize the impact to trees. HR Green team also walked the project with the Village Arborist, staked proposed improvements, and selected an alignment best suited to minimize tree impacts while minimizing utility conflict challenges.

HR Green provided preliminary and final design and resident engineering services on behalf of the Village of Hinsdale. The Woodlands Neighborhood Green Initiative included 20,606 Lineal Feet (3.9 miles) of Roadway Reconstruction, 92 Rain Gardens; 66,567 Square Feet of Area (1.53 Ac), 61,889 Cubic Yards of Underground Stormwater Detention Volume, 17,797 Lineal Feet (3.4 miles) of Storm Sewer, 17,523 Lineal Feet (3.3 miles) of Water Main Construction and 11,576 Lineal Feet (2.2 miles) of Sanitary Sewer Rehabilitation.