As an urban resident you make up the largest portion of Polk County and play a vital role in stormwater management. You can have a big impact on our environment even if you live in a downtown apartment or own a small residential lot.
Traditional urban development and landscaping designs cause rainfall to flow off roofs, sidewalks, driveways, and compacted lawns. Water flows into the street, down the storm drain and through the storm sewer to the nearest stream, river, or lake. Along the way, it picks up pollutants such as sediment, hydrocarbons, heavy metals, salts and nutrients. Polluted stormwater goes directly to water bodies without being treated.
Urban areas face many issues. With roads, houses, and other impervious surfaces replacing prairies and farm fields, less water soaks into the ground. This water now carries new pollutants to our river, streams, and lakes through storm sewer networks resulting in flooding, degraded water quality, and erosion.
Prior to European settlement, Iowa’s native prairies and savannas maintained soils with high organic matter and abundant pore space. This allowed the landscape to absorb rainfall, while shedding little runoff. Most rainfall infiltrated into the soil, where it recharged groundwater flow. Clear flows of groundwater fed and maintained Iowa’s river and lakes.
Iowa’s soil resources have been significantly altered by tillage-based agricultural practices and land development in urban areas. Consequently, less rainfall infiltrates into the landscape and more surface runoff occurs today.
Urban landscapes are dominated by impervious surfaces such as roadways, parking lots, and rooftops. Urban green spaces often feature turf grass with short roots over compacted soils. Such impervious and compacted surfaces decrease the amount of stormwater that can infiltrate into the soil, resulting in higher volumes of stormwater runoff. Stormwater carries pollutants into storm drains, which discharge directly into local streams and lakes. Urban runoff causes flashy flows that erode stream corridors and compound local flooding problems.
Runoff draining from urban areas can result in a variety of pollutants in the water. Daily activities on your property impact water quality in your watershed. Have you considered what you do that impacts water quality?
Some common urban pollutant sources include:
Yard Fertilizers – Phosphorous in fertilizers is a leading factor in algae blooms and other water quality issues.
Dog Poop – Dog poop is very high in bacteria. Because of dogs’ meat based diet, bacteria levels are much worse than in cow, pig, and other livestock sources.
Road Salts and De-icer – In late winter and early spring these chemicals drain to our local streams increasing salinity and harming critters.
Grass Clippings – This is one of the most common urban pollutants. If grass clippings are in the street they will be washed into the storm sewer where their natural nutrients, such as phosphorous, will cause negative effects on water quality.
Traditional development and landscape designs cause rainfall to flow off roofs, sidewalks, driveways, and compacted lawns. Water flows into streets, down the storm drain and through the storm sewer to the nearest stream, river or lake. Along the way, it picks up pollutants that degrade water quality. Learn more about what you can do to help reduce runoff and water pollution.
As a homeowner or urban resident there are several things you can do to reduce runoff and improve water quality. To start, ask yourself some questions
-Where does water go when it leaves your property?
-Do you have wet areas, or do you see water flowing when it rains?
-How are your soils, do plants have trouble growing?
-Do you want to do any landscaping?
By asking these questions you can begin to think about where could you utilize “Rainscaping” practices to manage your property’s runoff.
There are several stormwater, aka rainscaping, practices that can be implemented by homeowners and urban residents to manage stormwater and improve water quality. Essentially these practices can look like regular landscaping, but they can serve a range of purposes such as:
These practices rely on the natural functions of a healthy Iowa landscape, creating conditions where the ground can soak in and naturally filter the water. Many of these practices also utilize native prairie grasses and flowers that can have roots 5-10 ft. into the ground.
To address these water quality concerns, urban residents can utilize Rainscaping practices. Learn more about the many Rainscaping practices that can be used on your property to help reduce runoff and water pollution!
Types of Erosion
Sheet & Rill Erosion
Steam Bank Erosion
Phase I and II cities (44)
Polk Soil and Water Conservation District
1513 North Ankeny Blvd., Suite 3
Ankeny, IA, 50023
Polk Soil and Water Conservation District is an Equal Opportunity Employer.
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