100%
stormwater - ANSWERwater that starts as precipitation, flows overland or through storm sewers to
surface waterways
combined sewer - ANSWER60% of philly
impervious surface - ANSWERstormwater caused by
stormwater is important - ANSWERbiodiversity changes, altered hydrology, stream erosion, flooding,
pollution
retain, slow down, return, pay - ANSWERwhat can be done about storm water
separate sewer - ANSWER40% of philly
retention ponds and stormwater wetlands - ANSWERretain
slow down - ANSWERswale
surface runoff and inputs of stormwater sewers - ANSWERincrease infiltration by decreasing
rain gardens - ANSWERCollect surface runoff in a planted low lying depression
Native plants
Cuts down on the stormwater entering a stream
urban green alleys - ANSWERControl flooding and stormwater inputs
May be funneled into retention ponds