Climate Change & Water


Impacts on Sea Level and Water Pollution


Pittsburgh's three rivers; photo via Wikimedia Commons

• Sea levels are rising rapidly along Pennsylvania’s shoreline as the Delaware Valley is sinking at the same time as ocean levels rise [12]. Sea level rise is expected to increase the risk of flooding in the Delaware Estuary which extends into Philadelphia. For instance, under a medium-range sea level rise scenario, flooding events (storm surge) in the estuary exceeding 4 feet (above high tide line) is more likely than not by 2040 [25].

• One study conducted by the US Army Corps of Engineers and local partners found that the annual mean streamflow may increase by 15 to 25 percent in the Ohio River basin of SWPA by mid and late century. The same study found that annual maximum streamflow might increase by 15 to 25 percent by mid-century (2041-2070) and by 25 to 35 percent by late century [8].

• Peak spring stream flows in Pennsylvania are expected to occur 10 to 14 days earlier and summer low flows are expected to last about a month longer [9].

• Water quality may suffer as a result of more extreme precipitation events with associated increase in runoff. Runoff can carry increased sediment loads and pathogens. Higher water temperatures and heavy nutrient-rich runoff can also lead to increased algal blooms in lakes [10].

• Local stream temperature is expected to be altered by changes in future air temperature and precipitation, potentially affecting local ecosystem health by leading to shifts in habitat and species distributions [11].