Narrative:
One major goal of the project was to integrate the new building into the natural ecosystems of the site and to restore the seasonal watershed creek. Stormwater from new and existing hardscapes were drained to newly created bioswales, allowing sediments to filter out of the water prior to rejoining the stream and creating a rich new habitat. Rain leaders on existing buildings were disconnected from the storm sewer, and were channeled through runnels, visible in the sidewalks to new bioswales.
Roof runoff from the new construction is captured in a 15,000 gallon underground cistern, reducing unfiltered runoff into the creek and wetlands. This water is mechanically filtered and used in the building’s cooling towers and toilet flushing systems, reducing potable water use. Water efficient bathroom fixtures, including waterless urinals and dual flush toilets, reduce water use overall. The underground storage tank doubles as a thermal energy storage tank, and is several degrees cooler than incoming city water.
design is based on native, drought-tolerant species to minimize irrigation. The irrigation system has a weather-based evapotranspiration controller that calculates water supplies to each plant zone on a daily basis, based on current weather data and evapotranspiration rates.
Metrics:
Percent reduction of regulated potable water:
76%
Is potable water used for irrigation:
Yes
Percent of rainwater from maximum anticipated 24 hour, 2-year storm event that can be managed onsite:
30%
Water Cycle
source: http://www.aiatopten.org