Hakone Koi Pond upgrade project is set
The Hakone Foundation and the City of Saratoga are hosting a ground-breaking ceremony for the Hakone Koi Pond Sustainability Project on Sept. 28 at 2:30 p.m. at Hakone Estate and Gardens.
The project includes a new pump house and filtration system to ensure healthy koi and improve water quality. These improvements were identified in the Hakone Master Plan, approved in 2016.
An evaluation of the current condition of the koi pond revealed four key issues: The koi have health problems and fatalities likely caused by water temperature fluctuations and high levels of ammonia, nitrate and bacteria; the filtration equipment is only partially operating—existing pumps, pipe and vacuuming systems are inadequate and the UV disinfection system is not working; the water quality varies due to surface water runoff, and overfeeding fish results in an accumulation of organics and bacteria that are not processed by the water system; and the pond requires a high level of fill water, suggesting that there’s significant leakage.
Hakone began shortterm improvements, which included doubling the flow of water through the pond, reworking the filter and UV systems, rigorously vacuuming, reviewing feeding procedures, monitoring temperature, ammonia and nitrates and determining the exact cause of poor koi health.
The long-term improvements, which will begin following the ceremony, include switching the filtration system from a sand filter to a bead filter and UV system, and doubling the water flow; rebuilding the entire pool and evenly distributing supply and return pipes; deepening the pool in at least one area to give fish a sanctuary from predators; moving equipment away from public observation; developing a full wastewater recycling system; installing temperature controls to reduce stress on fish; and monitoring and flushing pond nitrates to control buildup in the system.
About $250,000 will be funded through the city’s the capital projects budget, and the remaining $100,000 comes from a Santa Clara County grant.
Addressing the koi pond issues is part of phase one of the Hakone Master Plan’s rollout. Phase two includes improvements to the Zen Garden House, Lower Moon Viewing House and the Cultural Exchange Center. Phase three includes renovations to restrooms, gate entries, the tea room and the caretaker’s house.
Admission and parking are free for the Sept. 28 event. For more information, call 408-868-1216.