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How urban runoff impacts our lives .

Our water and its vitality are the most simple
Open field
Forrest , grasslands and wetlands trap rainwater , allowing it to naturally percolate and filter back into ground .
form of our communities sustaining a healthy and economically viable lifestyle .
In the very early 1900s , most urban areas and municipalities across the nation built sewer systems to carry rainwater and sewage in the same pipe . This is called a combined sewer system . During dry weather conditions , the sewer system works fine . But , during heavy rainstorms , these combined flows frequently exceed the capacity of the sewer system and contaminants overflow into various waterways , causing a variety of environmental concerns . This is typically referred to as combined sewer overflow or CSO . large paved parking lots
When we pave and develop impervious hardscapes we take away the ability of rainwater to naturally filter back into the earth .
For more than 30 years , urban runoff has been recognized by almost every municipality as a significant detriment to the health and vitality of their geographical regions . Both stormwater and CSO discharges cause physical , chemical , biological and combined effects on receiving waters , seriously impairing beneficial water uses in most locations . In newer urban areas , some mitigation of flooding and erosion impacts have been achieved by certain stormwater management practices , but progress has been relatively slow because of high costs of retrofits or new systems . The current system is not working , nor will it be able to sustain our needs as urban areas become more densely populated . We need to find a better way to manage urban runoff .