Water is Energy

Pauline Souza, AIA

 

arcCA 10.2, water, energy, watsonville water resource
City of Watsonville Water Resources Center, WRNS Studio, all photos by Bruce Damonte

Water is one of the most precious resources we have, and we have to be mindful of its use. Although the world is 70 percent water, 97 percent of that is salt water, and 1.5 percent of the remaining amount is locked up in glaciers and polar ice caps. Currently, 1.1 billion people lack access to fresh water, and 2.4 billion lack adequate sanitation. Meanwhile, Americans extract 3,700 billion gallons of water per year—more than what is returned to the natural system.

In the United States, we use almost half of those gallons for thermoelectric power generation. Agricultural irrigation consumes another third. Water use in and around buildings accounts for about 47 billion gallons per day, or 12 percent. Likewise, 70 percent of the cost of water is tied to cleaning and transporting it, both of which require a significant amount of energy. Architects may not generally have much influence over the agriculture industry, but we have a significant role to play—not just in reducing that 12 percent of water used in buildings and their landscaping, but also in cutting energy use and in the process saving even more water. Especially in a state like California, where climate change threatens to worsen droughts, growing populations compete with farms for water resources, and the aging infrastructure is having trouble keeping up, every drop counts.

Like most architecture firms, WRNS Studio has known for a long time that water is a critical resource that needs more attention. Designing the City of Watsonville Water Resources Center recently in Watsonville, California, however, made us even more aware of the facts—and the urgent need to find better solutions in designing and constructing buildings to conserve water.

The Pajaro Valley’s Water Crisis
The Pajaro Valley encompasses all of Santa Cruz, Monterey, and San Benito counties— 79,600 acres, including agricultural land and the growing city of Watsonville. The valley’s agricultural economy produces $530 million in annual revenue but also consumes 85% of the county’s water. And 95% of that water is pumped from aquifers. Pajaro Valley currently pumps 69,000 acre-feet per year. That number is expected to increase to 80,000 acre-feet per year within the next three decades.

The combination of excessive pumping and severe drought conditions has led to salt water intrusion into the aquifers, which are below sea level and continue to pull water from the Pacific Ocean inland. To halt seawater intrusion, the water supply for agriculture would have to be restricted to 12,200 acre-feet/year—an 80 percent reduction, at an annual loss of $372 million to the economy.

Studies showed that one way to resolve this situation was to treat and recycle wastewater. So the City of Watsonville built a water recycling plant next to the city’s water treatment plant, providing recycled water to farmers throughout the coastal areas of southern Santa Cruz and northern Monterey counties. The wastewater treatment plant recharges the region’s aquifer with 4,000 acre-feet of water for irrigation annually and significantly reduces wastewater discharges into the Monterey Bay National Marine Sanctuary.

The City of Watsonville hired us to design the water resources center as a functional, educational, and visual extension of the water recycling plant it supports, consolidating three different city and county water departments into a workspace that would allow collaboration on issues of water management, conservation, and quality in the Pajaro Valley. The program included administrative offices, a regional command center, and a water quality lab. In addition, the building, its systems, and its surrounding land are intended to educate the public through exhibition and guided tours on the issues of water, energy management, and air quality.

Telling the Story of Water
The building’s architecture teaches in a variety of ways. The conference rooms were designed with community use in mind, and the facility hosts frequent tours for schoolchildren. The water resource center’s systems and controls are all visible, and almost every component of the building has a water-related story behind it.

Rather than channeling rainwater invisibly into a gutter system, the building allows rain to flow off of the roof, down rain chains, and into swales, where it is carried to retention basins, detained, and treated prior to infiltrating the groundwater system. This strategy makes the intersection of buildings and water explicit.

The water feature relies entirely on recycled water. During California’s dry season, the native son. While another client may have objected to these aspects on aesthetic grounds, our clients embraced them because they tell the truth about our particular climate. Working on this project really drove home for us how much the standard approach to design tends to conceal the natural processes of water and climate.

Placing Water at the Center
In initial discussions with the client, we decided that all design decisions had to tie back to water use. Whenever possible, the building and its landscaping reveal an underlying focus on water as a finite, invaluable resource. Because our clients were motivated to save water as much as possible, they pushed us to rethink our assumptions and dig deeper. That meant applying an unusual level of scrutiny to the design. Some things were obvious. The radiant floor is a closed-loop system, using the same water to heat and cool the building. The facility has low-flow faucets and showers.

But beyond those measures, for each material that we considered, we asked, “Where does it come from? How is it made? How much energy and water does it take to make it? Can we live without it?” Because our clients are steeped in the technical aspects of water, they could provide extensive information about the composition of water, water quality, and the costs of water, which informed the decisions of our mechanical and plumbing engineers. The structural engineer identified ways to construct the building with fewer materials. By reducing the amount of wood by 50% compared to a conventional structural solution, we saved on the water and energy required to produce that wood. The wood, which comes from California redwood trees owned by the city and slated for fire hazard clearance, was custom milled eight miles from the project site and incorporated into the building’s rain screen cladding system.

Staying true to the larger mission—raising consciousness about the whole process of water—has changed the way we work. While we incorporated water conservation on past projects, we now approach each new project with water as one of the defining issues for the site and the building. We ask ourselves, “Where does it flow or land on the site? How will it re-enter the ecosystem? Where can we conserve and recycle?”

Pajaro Valley’s aquifer was drained because California consumes water in a way that isn’t sustainable. The water recycling plant and the water resources center are trying to raise awareness not just about recycled water, but also about the ways we live. After all, the cost to bring in recycled water is higher than the cost of drawing on the aquifer. When we all use water more resourcefully, recycling won’t be necessary. Architects have a key role to play in telling this story.


Author Pauline Souza, AIA, LEED AP, is associate partner and director of green services at WRNS Studio in San Francisco. She is a contributing member of the National AIA Committee on the Environment Communications Committee, as well as a board member and green schools advocate for the U.S. Green Building Council’s Northern California Chapter.


Originally published 2nd quarter 2010, in arcCA 10.2, “The Future of CA.”