Rainscaping
What is rainscaping?
Rainscaping refers to the process of enhancing a landscape or property to better manage the stormwater draining off that area. Rainscaping seeks to interrupt the "urban water cycle" before the stormwater flows into the storm drain. Traditionally we have sought to pipe away stormwater as quickly as possible to the nearest river or stream, a process that degrades ecosystems, lowers property values, and raises taxes. In a phrase, rainscaping can be thought of as managing rain water where it lands.
Why is rainscaping important?
The below pictures of Plaster Creek were taken less than 24 hours apart. They illustrate the rapid change in water level that occurs after a rain event called a stormwater surge. Stormwater surges on Plaster Creek are unnatural events that exist because of the way we deal with stormwater—we pipe it directly to our streams and waterways as quickly and efficiently as possible. These surges can create dangerous flash floods, but it's not just the change in water level we're concerned about. Higher levels of E. coli bacteria, sediment (see how brown the water is in the picture on the right), nutrients from fertilizer, industrial metals, and other pollutants wash into the creek.
Types of Rainscaping
Native landscaping, sometimes called native revegetation, is replacing lawn grass or non-native landscaping with native plants.Â
Because native plants have been here since before European settlement and are adapted to our local climate, they need far less care and maintenance to survive.Â
Because they’ve existed in the area for so long, native animals (including pollinators) naturally recognize them as food and shelter. They also play critical roles in the life cycles of our native insects that depend on specific local plants for nourishment and protection.Â
Many residents, gardeners, businesses, and landscape designers are turning toward native landscaping for its more sustainable maintenance needs and its many benefits to our ecosystem and communities.
Volume reduction/infiltration
Increases infiltration rates by a factor of 10 or more ( Manual 2016)
Water quality improvement: Native landscaping can reduce nitrogen and phosphorus-based pollutants because they don't require fertilizers and can remove these nutrients from the soil ().
Air quality improvement
In the Midwest, the use of lawn equipment in a metropolitan area can cause up to 25 times more daily air pollution (in tons of VOC) than a large auto assembly plant. Native landscaping reduces VOC emissions and improves air quality by eliminating the need for regular mowing ().
Carbon sequestration
Adding more biomass to soil improves the soil’s ability to sequester atmospheric carbon. Because native plants have more biomass in their root systems than traditional lawn grasses, they are able to sequester more carbon ().
Biodiversity/habitat
Native plants provide food and habitat for native species—especially pollinators. Installing native plants in urban spaces is especially important in the protection and restoration of native biodiversity.
How much does native landscaping cost?
Native landscaping is fairly inexpensive. The costs involved typically include:
Native Plants: $65-75 per 38-plug flat (one flat for every 30 sqft)Â
Mulch: $25-35 per yard (1/2 yard of mulch for every 80 sqft)Â
Compost: $35-45 per yard (1/2 yard of compost for every 80 sqft)Â
Labor: $150-200 per hour
How is native landscaping maintained?Â
Native landscaping requires the most maintenance during the first few months after installation. A new native planting should be regularly watered and weeded to give the plants the resources they need to build established root systems. Once the plants are more mature, minimal maintenance is needed as the plants are adapted to thrive in Michigan climate conditions. However, mature native landscaped sites should still be weeded and watered during dry periods. Additionally, a new layer of mulch should be added every year.
Additional information
(SEMCOG 2008)Â
The classic rain garden is designed to be an endpoint for stormwater that runs off a property or off of some type of impervious surface (a surface that water can't drain through, eg. a parking lot, a rooftop, or, to a certain extent, a lawn). Planted with native plants that don't require added nutrients or pesticides, a rain garden captures stormwater and allows it to percolate through soil layers and into the water table in a slower, healthier, and more natural way. This percolation process filters out sediment and other pollutants that would otherwise flow into our local waterways, and it reduces harmful flash floods that can be common to urban waterways.
For a more technical overview of rain gardens, complete with calculations, procedures, and site analyses, check out the
Interested in creating a rainscape? Check out how to build your own rain garden.
Bioswales are large-scale rain gardens designed—often by engineers—for heavy-duty stormwater management. They typically have an overflow option to a storm drain and are used to collect stormwater from a large area like a parking lot. They are often less formally planted and manicured than rain gardens.
This bioswale was seeded and planted with native prairie grasses and wildflowers and captures the stormwater from a 2 acre parking lot on ÃÛÌÒapp’s campus. The prairie is now mature enough to have prescribed burns every few years to manage weedy species and encourage the native plant growth. The water must travel through the large s-curve and rise above a standing pipe before it can spill over into a wetland, something that rarely happens. This project is a great example of how native habitat restoration can be used in responsible stormwater management.
Vegetated buffers are an important practice for farmers or anyone who owns land on the creek or any of its tributaries. Keeping on Filling the banks of the creek and its tributaries, no matter how small, with trees, shrubs, grasses, and/or wildflowers benefits the water quality in several ways:
- Erosion control: Plant roots form extensive networks in the soil, helping hold it in place and keeping banks from eroding and washing into the creek.
- Shade: Trees and shrubs provide shade to the creek and its tributaries. This cools the water, improving natural habitats.
- Filter: Plants intercept runoff, helping filter out nutrients and trapping sediment. In an agricultural setting, they help filter runoff that can contain animal manure and E. coli bacteria, preventing health risks downstream.
Floodplain restorations are done next to waterways to stabilize eroded stream banks and create space for waterways to spread out and slow down, decreasing flooding and lowering the amount of sediment in the water. Native floodplain plants help to filter out pollutants and prevent erosion while providing rich habitat for native wildlife.
Other ways to protect the creek
Rain barrels
More and more homeowners are capturing stormwater from their roof by attaching their gutters and downspouts to rain barrels. The typical rain barrel holds 55 gallons of water, and it can fill up with just a half inch of rain! Rain barrels can be used to water vegetable or flower gardens, or they can be used together with a rain garden to catch the first 55 gallons of stormwater, which can later be used to water the rain garden during hotter, drier times.
Trees
Trees are an excellent solution to stormwater issues no matter where they are in the watershed. Leaves and branches provide lots of surface area to intercept rainwater, slow-releasing it as droplets are shed to the ground. Trees take up several gallons of water per day, as well as excess nutrients that would otherwise pollute the watershed.
Fall leaves
Mulch, compost, or collect your leaves, but don't leave them in the streets. Check out our Leaf-let for more information about fall clean-up.
Everyone can do something
There are several simple, smaller steps we can all take to improve water quality in Plaster Creek, the Grand River, and Lake Michigan. These include moving pet waste to a trash can, reducing the amount of lawn fertilizer you use, or washing your car on the lawn or gravel instead of the driveway.Â
For more information about Rainscaping and the Grand River, check out (Lower Grand River Organization of Watersheds) for many great resources.