The Clark’s three-tiered reflecting pool serves functional as well as aesthetic purposes. It integrates with stormwater management, rain water collection, landscape irrigation, and heating and cooling systems, conserving water resources and protecting nearby riparian habitat. Since the
Lesser known is that the reflecting pools serve a functional, environmental, and water conservation role as well. They are part of a system that integrates captured rainfall, site stormwater, and foundation water with landscape irrigation and building systems, such as climate control and toilet flushing. The system uses what might previously have been treated as wastewater as a resource, rebuilds groundwater through infiltration on site, offsets potable water use in the building, and improves the health and performance of surrounding wetlands and streams by mitigating storm events and runoff.
While today this sort of approach is becoming more standard with the design community’s recent focus on water conservation and management, when the Clark expansion program began more than ten years ago it was not as much part of the national dialog. “In 2008 or 9 or 10, when we were picking it up in detail, even then we didn’t think about water the way we do today,” said Gary Hilderbrand of Reed Hilderbrand. “I would say we were evolving along with the cultural evolution about the importance of water and conserving potable water and thinking of every drop of rain and available groundwater as part of the resource budget. Today we do it on all our projects, but even five years ago that was not commonplace.”
Cristopher Leonard / Courtesy Gensler
The idea originated with the executive architect, Gensler, which, in addition to coordinating the project’s various design teams and consultants, also provided sustainability services. (The project is pursuing a LEED v3 Silver rating.) “As part of our sustainable work, we looked at different systems and listened to the other consultants about where they could make points, where they couldn’t, and where they were struggling,” said Gensler principal Madeline Burke-Vigeland. “They kept talking about water, especially foundation water and how do we get rid of it. The mechanical teams also needed water for the building systems. My colleague, Ben Koenig, just sort of had a coconut on the head moment and said, ‘what if we connected all these systems and used it to feed the water feature?’”
A network of drains and pipes collects water in a series of retention tanks and reservoirs. The system collects rainwater from the site and from the roofs of the buildings. It collects ground water from the campus’ seven geothermal wells and from the center’s foundation. Ando insisted on placing 60 percent of his building below grade and, due to the site’s high water table and heavy soils, this resulted in 60,000 gallons of groundwater pooling around the foundation per day. The collected water flows into the reflecting pools, which cover about an acre of ground and, at an average of 13 inches deep, hold about 280,000 gallons of water. Two-thousand gallons of water flow through the pools per minute. This flow also feeds into the campus’ cooling tower and toilet flushing system. Downstream discharge is filtered in the lowest of the pool’s three tiers as well as in constructed wetlands, ensuring that no contaminants reach Christmas Brook.
While the system is still going through final commissioning, and final performance modeling has yet to be revealed, it is designed to reduce the campus’ water usage by 50 percent, or 1 million gallons annually.