OpenStreetMap

Does this underground "river" added in https://www.openstreetmap.org/changeset/130927665 actually exist? My understanding is that the original creek was basically obliterated -except when the sewer system gets completely overwhelmed and floods the streets- and the ordinary municipal combined stormwater-sewer network is what the Mission District currently drains into. There's a small treatment facility at the end of what remains of Mission Creek.