Rain Garden
Rain gardens are depressional areas landscaped with perennial flowers and native vegetation that soak up rainwater. They are strategically located to capture runoff from impervious surfaces, such as roofs and streets.
As cities and suburbs grow, increase storm water runoff from impervious surfaces becomes a problem. As more impervious surfaces are added to our communities, it is more important than ever to help rainwater infiltrate. This protects water quality and reduces storm water runoff.
Native plantings are beautiful additions to any urban landscaped. When established, native landscapes are low maintenance areas that provide great habitat for insects and birds adapted to Iowa. Their deep root system (up to 12' deep) increase soil organic matter, builds soil quality, and helps retain and infiltrate storm water.
Native plants do not establish as quickly as traditional lawns. The plants establish their deep roots before they put much energy into above ground plant growth. Once the roots are established, the plants will dominate and bloom beautifully. This may take two years or more.
CLICK HERE FOR DETAILED DIAGRAM OF NATIVE LANDSCAPING ROOT SYSTEMS
Pervious paving allows water to infiltrate into layers of limestone placed below the paving and then into the soil and groundwater below. By infiltrating most of the storm water on-site, the amount of water and pollution flowing into storm sewers and directly into rivers and streams is reduced. This helps protect water quality, maintains more stable base flows to streams, reduces flood peaks, and reduces stream bank erosion. With infiltration, groundwater is recharged and streams are replenished with cool, clean groundwater in a more natural way.
Pervious paving can be considered in the following situations: parking lots, driveways, sidewalks, bike paths, walking trails and patios.
The Dubuque County Conservation Board recently completed construction on their porous asphalt parking lot at the Swiss Valley Nature Center. POROUS ASPHALT Stop out and see the project! 8/09 A permeable paver driveway and sidewalk has been construction at the Nature Center. Stop out and see the practice.
PERMEABLE PAVERS WATER INFILTRATING PAVERS POROUS CONCRETE
Bioswales are storm water runoff conveyance systems that provide an alternative to storm sewers. They can absorb flows or carry runoff from heavy rains to storm sewer inlets or directly to surface waters. Bioswales improve water quality by infiltrating the first flush of storm water runoff and filtering the large storm flows they convey.
The majority of annual precipitation comes from frequent, small rain events. Much of the value of bioswales comes from infiltrating and filtering nearly all of this water.
Native plants are most desirable within the bioswales as their thick, heavy cover best filters out contaminants.
Bioretention areas can provide excellent pollutant removal and recharge for the “first flush” of stormwater runoff. Properly designed cells remove suspended solids, metals, and nutrients, and can infiltrate an inch or more of rainfall. Distributed around a property, vegetated bioretention areas can enhance site aesthetics.
Conventional dry detention practices are used to reduce the peak discharge and detain runoff for a specified short period of time. Detention volumes are designed to completely drain after the design storm has passed. Detention is used to meet overbank flood protection criteria, and extreme flood criteria where required
A constructed shallow water ecosystem designed to simulate natural wetlands.
Soil is an important, but often overlooked, component of water management. Soil quality refers to the ability of soil to perform its functions. Soil is especially important in regulating runoff of storm water and in supporting trees, shrubs, lawns and gardens. Urban activities, such as construction grading, often result in erosion, sedimentation and soil compaction. Management practices are often needed to restore soil quality after development.
Green roofs, also known as vegetated roof
covers, eco-roofs or nature roofs, are
multi-beneficial structural components that help to mitigate
the
effects
of urbanization on water quality by filtering,
absorbing or detaining rainfall. They are constructed of a
lightweight soil media, underlain by a drainage layer, and a
high quality impermeable membrane that protects the building
structure. The soil is planted with a specialized mix of
plants that can thrive in the harsh, dry, high temperature
conditions of the roof and tolerate short periods of
inundation from storm events.
