Our focus this week, the Mill Creek watershed, is a perfect example. This watershed, named for its main tributary, drains water from portions of Greene, Summit and Millcreek Townships and the city of Erie into Presque Isle Bay. Stream alterations, deforestation, development and poor industrial practices carried a high environmental and economic price tag that was never considered as the area grew and prospered.
Once-pristine streams became major sources of pollution, carrying human waste, industrial pollutants and sediment into Presque Isle Bay. This contributed to the bay being designated an Area of Concern in 1991 as one of the most polluted spots in the Great Lakes.
Changes made to the aquifer also caused major floods. The most serious was the Mill Creek flood that occurred in 1915 after a series of storms produced more than 5.77 inches of rain in 13 hours. Before it was over, 36 people died and 225 homes were damaged or destroyed, along with 300 commercial and other buildings.
These costly problems could have been prevented if the streams, wetlands and forests had been valued for their important roles in providing habitat, protecting water quality and preventing damaging floods.
When Erie County was opened to settlement, it was covered with a dense forest and clean streams that flowed continuously. Wildlife, including native trout, was plentiful. Unfortunately, humans altered the watershed and the flow of Mill Creek and the other tributaries. They cleared the forests, built mills and dams on the streams, drained and filled wetlands and marshes so they could build on them, sunk wells and pumped groundwater, channelized the streams, and created impermeable surfaces, such as roads, parking lots, sidewalks and buildings, too close to the water.
Ravines were gradually filled in. Protective riparian buffers, or areas of trees, shrubs and other plants next to, and upslope from the streams, were removed and development occurred right up to the stream banks. Rain and snow melt could no longer be filtered or soak into the ground to replenish groundwater and gradually enter the stream. Instead it became runoff that generated erosion and carried sediment and pollutants.
Sections of Mill Creek, Garrison Run and other streams disappeared into concrete pipes that were covered over with impervious roads, buildings and parking lots. The pipes carried runoff, sewage and industrial waste, including heavy metals, DDT, dioxin, polychlorinated biphenyls (PCB’s), and a number of pesticides, into Presque Isle Bay and Lake Erie.
These activities affected the natural water cycle and the streams began to suffer from too much or too little water that could no longer support healthy habitats for fish and other animals.
Humans also suffered environmental and economic consequences. Fish advisories limit fish consumption. Increased treatment for drinking water and wastewater, damaged fisheries, flood damage and the restoration of Presque Isle Bay and Lake Erie has cost taxpayers billions of dollars.
The good news is we can protect many streams in the Lake Erie watershed by avoiding these mistakes. Learn more about your watershed and get involved in protecting your water sources. Read more about the AOC at www.pibpac.org/
ANNA McCARTNEY, a communications and education specialist for Pennsylvania Sea Grant, can be reached by e-mail at email@example.com.