Photo courtesy of the Volunteer Park Trust: The fate of the Volunteer Park Reservoir is still being decided.
Photo courtesy of the Volunteer Park Trust: The fate of the Volunteer Park Reservoir is still being decided.

The Volunteer Park Sustainability Coalition provided findings from its park-wide feasibility study for improving water usage during an open house Thursday in the conservatory.

At more than 40 acres, Volunteer Park includes a lot of green space, but also a sizable amount of impervious surfaces. It’s home to the Seattle Asian Art Museum and Volunteer Park Conservatory.

A large feature also in the park is the Volunteer Park Reservoir, a potential asset for reducing a large amount of water usage in the park, said Adam Young, who was commissioned to craft the sustainability report, funded by a $25,000 Department of Neighborhoods 2015 Small and Simple Neighborhood Matching Fund Grant.

“It could handle all of our water needs for the park all by itself,” Young said.

Seattle Public Utilities took the reservoir out of service in April 2013 for a two-year decommissioning test. It had been a standby in case of fires during the State Route 520 bridge replacement project, but does not provide potable water. A seismic evaluation for the city’s drinking water distribution, which included a post-earthquake storage scenario for the Volunteer Park Reservoir, was delayed to mid-2017 due to a need for more study, according to an August 2016 SPU public notice.

Despite its potential benefits to the park, Young said it could not be included in the feasibility study. SPU is not considering any future uses for the reservoir until the seismic report is complete and there is a decision whether to officially remove it from the city’s drinking water distribution system.

Anthonio Pettit with Friends of the Conservatory, a Volunteer Park Sustainability Coalition member, said the reservoir would require major improvements to provide potable water. It’s part of the Olmsted Brothers’ design for the historic landmarked park, meaning it has to be a water feature, Pettit said, but it doesn’t have to be a reservoir.

While the reservoir is currently off the table, the water study did identify other opportunities for conservation.

Two-thirds of water consumption in the park is through irrigation.

“It’s the second big elephant in the room,” Young said.

The park benefits from about 32 million gallons of rainwater, but about 7.8 million gallons are imported to cover irrigation needs annually.

Young said the first step to reducing that amount is to update landscaping with more drought-tolerant Northwest native species of plants, then improve the system. A vegetation master plan also calls for planting more trees in the park, Young said.

Volunteer Park had one of the worst issues of leaking irrigation in the country, Young said, but major repairs were completed while the study was still in progress. It will take another year to determine if that provides a significant savings, he said.

The reservoir has a pump house that could be used for irrigating the park, but that again is not currently an option.

A popular water feature in the park is a wading pool near the playground. Young said about 22 percent of the park’s water usage goes toward the daily filling of the pool in the summer — 33,000 gallons from the Cedar River Watershed.

“Every day, fill and dump,” he said. “We’re paying to import the water, we’re paying to export the water.”

The study states the annual cost for filling the wading pool is $24,000.

Because the pool is treated with chlorine, the water can’t be diverted each night toward irrigating the park. During the summer, Young said, close to 50,000 gallons of water is used for irrigation each night.

It’s possible to counteract the effects of the chlorine with chemicals, or store the used water for an extended period of time. A pump house and filtration system is another option.

“There are a variety of other methods,” Young said. “Parks has shown tremendous interest in this because they have 60 wading pools around the city.”

Pamela Kliment with Seattle Parks and Recreation said there are issues with a pump house, including worker safety for undergrounding and landmark issues for above ground.

SPR has already approved the study, Kliment said, which will be updated with feedback collected during Thursday’s open house.

“We don’t bring anything to the table that hasn’t been vetted,” Kliment said.

Young said the wading pool is empty during winter, and could be used to collect rainwater during those months for the conservatory’s constant watering needs.

A stormwater system was added in the park back in the '80s, to handle the rainwater coming off roadways and structures in Volunteer Park. The stormwater is piped to a detention tank, where it then merges with the sanitary system in a combined sewer.

According to the coalition’s Park Sustainability Improvement Measures report, the system can overflow during heavy storms. That overflow goes into the Puget Sound without being treated.

Improvement measures being explored include collecting rainwater from rooftops, using the conservatory’s stormwater system to collect rain in cisterns for irrigation and various rain gardens that could handle overflow events. There are several areas around the park where such infrastructure could be added, Young said, including the former site of a west playground.

Pettit said the next steps will be fundraising and applying for more grants, to design identified sustainability improvements.

The EPA had been identified as a potential grant-funding source, Young said. It’s unclear with the new administration whether that will be a viable option moving forward.

“There’s going to be a lot of competition for grants and fundraising,” Young said.

The Volunteer Park Sustainability Coalition is a partnership between the Volunteer Park Trust, Seattle Art Museum and Friends of the Conservatory.

Pettit credits longtime Friends of the Conservatory member Audrey Van Horne for the coalition’s formation. Van Horne spearheaded the replacement of aged and rotted wood sections of the conservatory with aluminum. She staffed the welcoming table during last Thursday’s open house.

“It saves the planet,” Van Horne said about conservation work, “so it’s something we care about.”