GrokSurf's San Diego

Balboa Park Golf Course Lily Pond

San Diego’s Balboa Park is a beautiful green oasis that includes the zoo, a golf course and recreation areas benefiting residents, tourists, local businesses, a fair amount of wildlife and the city, but it is a huge water user.

Balboa Park’s water demand is around 1,240 acre-feet per year (1.5 million gallons per day) according to San Diego’s 2005 Recycled Water Master Plan Update. 80% or more of that goes for irrigation. If recycled water were available to Balboa Park, we could conserve around 1 million gallons of drinking water per day!

The Evenson fountain starts up at noon

For years, the city has been encouraging water reuse, but many areas, including Balboa Park, cannot participate due to lack of infrastructure. The city has been studying proposals to address the possibilities for Balboa Park and other large water users, but it is a long, complicated process. Much more time will pass before a proposal is chosen and money is found to address this need.

Potential recycled water users in the area

The water stairs are still working

So far, it appears there are three possibilities:

1. Extend the existing recycled water pipeline from near the North City Water Reclamation Plant, tunnel it under Mission Valley and deliver it to a storage location near the park. This is the most expensive proposal and therefore would encounter great resistance, but I favor it because it has numerous beneficiaries, including Mission Bay Park, as indicated in the chart below. I believe they could employ an inverted siphon to move the water across Mission Valley to avoid or minimize pumping costs. Also, the city promised the federal government that it would reuse at least 50% of the plant’s water; this initiative would help achieve that goal.

2. Tap groundwater underneath the park. Previous studies have revealed potentially significant amounts of water, but pilot production wells need to be drilled and monitored to determine whether this aquifer can supply an adequate amount of usable water, according to Marsi Steirer, Deputy Director of the San Diego Water Department. Monitoring wells have already been installed. Additional information about USGS hydrogeological studies in San Diego is here: http://ca.water.usgs.gov/sandiego/.

They're replacing grass with something better at the pool Casa del Prado fountain

3. Intercept a sewer line running through Florida Canyon and provide tertiary treatment of the wastewater bringing it up to reuse standards with a small MBR (Membrane BioReactor) facility. This option would probably be just enough for only the park, and might even need supplemental city water during periods of low sewer flows.

There’s one other proposal, to build a reclamation plant in Mission Valley to serve Balboa Park, Mission Bay Park, and the Riverwalk Golf Course but I haven’t found further discussion about it.

Of course, the cost of producing and delivering reclaimed water for reuse in Balboa Park would be great. The city’s estimate for a pipeline extension project is in the neighborhood of $65 million, and the cost of retrofitting park plumbing could be $1 million.

Many people might imagine that our current water shortage is temporary and oppose such expensive measures, but the reality is we have exhausted the supply of imported water from the California and Colorado River aqueducts and the cutbacks we’re now seeing are just the beginning. Meanwhile, our population continues to grow, accompanied by new development.

Casa del Prado patio/courtyard

It’s a pessimistic note to end with, but I’m afraid that even if we do everything right and get more projects like this done, we may manage only to reduce the speed of a slide into a deep water emergency. To more effectively address our long-term needs, not just for the park, I think the pipeline extension option is definitely needed. Probably all three options should happen, in some complimentary configuration. Clearly more needs to be done.

Behind the Botanical Building: watering not permitted after 10am? Oops!