http://www.scpr.org/programs/offramp/2016/08/24/51528/bringing-back-the-arboretum-s-sludge-filled-baldwi/ KPCC .org: "Bringing back the Arboretum’s sludge- filled Baldwin Lake" (aired 24 July 2016)] Since the early 1950s, the Lake has functioned as a collection basis for 155 acres of urban watershed to the north.