A long-vacant city-owned parcel next to Eaton Blanche Park is about to become two things at once: a passive park with gardens, walking paths and a dog run, and an underground stormwater capture facility designed to clean polluted runoff before it reaches the Los Angeles River. … The Eaton Wash Stormwater Capture Project sits on a vacant city-owned parcel east of the Eaton Wash Channel, adjacent to Eaton Blanche Park. The site was first identified as part of the city’s Storm Drain Master Plan, according to the Public Works Department. Underground, the system will divert storm and dry-weather flows from the channel into a subterranean concrete basin for treatment and infiltration, with a capture capacity of 3.4 acre-feet, according to a state environmental filing.