Restoration
Restoring health and beauty to the Plaster Creek watershed involves restoring the relationship between its residents and the creek, as well as restoring the creek’s health with multiple forms of green infrastructure.
The land around Plaster Creek has historically and presently been altered by many types of human development, including farming, logging, mining, manufacturing, housing, paving, and industrializing. Some of these types of development affect the creek directly, while others do so indirectly by changing how and where water flows into the creek. Stormwater from rainfall in developed areas often cannot soak into the ground where it falls, so it becomes runoff, picking up sediment, bacteria, oils, trash, and other pollutants as it flows, and enters waterways via storm drains. This is called nonpoint source pollution. The effects of pollution on our waterways include:
- Increased flooding and erosion during storms due to high volumes of runoff
- Contaminated surface runoff with sediment, bacteria, and nutrients
- Increased water temperature due to runoff from hot surfaces and lack of shade from trees
- Decreased biodiversity and habitat for native plants and animals
Nature-based solutions
Nature-based solutions are strategies that use natural processes and ecosystems to address societal challenges, such as climate change, biodiversity loss, and water security. These solutions harness the power of nature to provide benefits to both people and the environment.
One aspect of nature-based solutions is Green Stormwater Infrastructure, which is a set of practices designed to decrease the negative effects of our built environment on our natural ecosystem.
GSI often uses plants, soils, and other natural resources to mimic nature and better manage stormwater to create healthier urban environments. Done on a small or large scale, GSI is beneficial for returning the creek to a healthier state and supporting our natural environment.
Implementing Green Stormwater Infrastructure
Plaster Creek Stewards works alongside community members to implement various GSI restoration strategies that restore not only the creek, but also the relationship between people and the earth. With this in mind, we invite community members to help grow native plants at the greenhouse, then join in envisioning, planning and restoring native landscapes in their communities.
What restoration looks like
Native Plants and Trees
Rainscaping
Rain Gardens
Other nature-based solutions
What are permeable pavers?
Permeable Pavers are concrete bricks with ADA-compliant gaps between them that are either filled with gravel or left open. These gaps allow surface runoff to infiltrate through a stone layer into the soil below rather than flowing directly to the nearest storm drain.
Permeable pavement also requires less deicing salt in winter than traditional impervious surfaces because it can store heat and keep soil temperatures above freezing, which encourages thawing (Toronto and Region Conservation Authority, 2008; Roseen et. al, 2012).
Volume Reduction/Infiltration
Permeable Pavers have been found to surface runoff volume by at least 60% even on clay soils (Jaber, 2015). During winter months, they continue to effectively infiltrate surface runoff because of the heat storage effect described above.
Water Quality Improvement
Permeable Pavers have been found to be quite effective at reducing pollutant loads, although significantly less so with dissolved pollutants, as shown below (SEMCOG, 2008).
Phosphorus: 30-90% reduction
Nitrogen: 30% reduction
Total Suspended Solids (TSS): 65-100% reduction
Biodiversity/Habitat: Permeable Pavers don't provide native biodiversity or habitat for native species on their own, but can be used in conjunction with other GI practices like Rain Gardens or Filter Strips to do so.
How much do Permeable Pavers Cost?
Permeable Pavers tend to run $10-17 per square foot installed. One popular brand that has been installed in the Grand Rapids area, PaveDrain, is advertised to cost $10-13 per square foot installed. This number includes:
Material: $6–7/sqft
Aggregate layer: $2–3/sqft
Installation: $2–3/sqft
Additional costs may be incurred for leveling and/or excavation of the site (PaveDrain 2022).
How are Permeable Pavers Maintained?
The gap between Permeable Pavers allows water to infiltrate into the native soil. However, over time these gaps can become clogged with sediment or tree litter, especially in climates like that of Michigan where trees shed their leaves every year. This can reduce the effectiveness of Permeable Pavers. To prevent this, Permeable Pavers should be inspected for clogging after rain events and commercially cleaned at least once a year. There are a variety of local commercial parking lot cleaning services in Grand Rapids, and a typical urban parking lot under 0.5 acres can usually be vacuumed for about $200-400.
Additional Information
Evaluating the potential benefits of permeable pavement on the quantity and quality of stormwater runoff (Upper Midwest Water Science Center 2019)
Minnesota Stormwater Manual—Permeable Pavement Page (2020)
Proposal for the Use of Pervious Pavement for Repaving the Belmont High School Parking Lot (Colton 2013)
Sustainable Technologies Evaluation Program—Permeable Pavement Page (2019)
Commercial Parking Lot Cleaning Providers:
Large paved spaces like parking lots do not allow rainwater to seep into the ground naturally. When it rains, water running off a parking lot goes into storm drains, which empty directly into our waterways.
In Plaster Creek, this causes the creek’s water level to rise dramatically and its banks to erode. This runoff also carries pollutants such as sediment, gravel, asphalt, and heavy metals into the creek. When these pollutants wash downstream, they harshly affect the water quality for those living there.
Retrofitting parking lots can reduce flooding and improve water quality for downstream communities.
Retrofitting with bioswales
One way to retrofit a parking lot is through the addition of a bioswale.
A bioswale is a rain garden that is large enough to capture stormwater from a large area. Water coming off the parking lot flows over gravel channels and into sediment traps which slow down the water so pollutants can settle out. The water is also given time to cool down and seep naturally through the soil into a storm drain or directly to the creek.
Native plants cover the bioswale, using rainwater for growth, improving pathways for water to go into the soil, filtering out pollutants, and creating a diverse habitat for pollinators.
In September of 2022, the City of Grand Rapids will update water quality and retention standards to meet MS4 requirements. Developers will need to capture and treat more of the surface runoff from their property than they have in the past. In some cases, developers will not be able to meet these new requirements due to limited space, poor soils, or other reasons.
To address this issue, Grand Rapids will also be launching one of the first stormwater credit trading programs in the nation.
If a property owner is going above and beyond city standards with their water retention practices, they have extra 'stormwater credits', which they can sell to developers who are unable to meet city standards.
Property owners just need to get their site approved, and then they can post their credits to an online marketplace, where developers can buy credits from within the same watershed as them. These transactions happen in the private sector, and it is up to the developer/buyer and property owner/seller to decide upon the terms of their individual agreement.
This new program provides an opportunity for property owners who retain excess stormwater runoff to not only help the environment through these practices but also sell these 'credits' at a rate of their choosing—effectively making money from implementing GI.
If you have any questions about Stormwater Credit Trading, please contact us: plastercreekstewards@calvin.edu
Because of their size and deep root systems, trees are especially adept at infiltrating surface runoff and improving water and air quality. Unfortunately, most urban trees do not survive long enough to meet their full potential environmental impact (Minnesota Stormwater Manual 2017). This is largely due to limited space for root growth, lack of access to water, and soil compaction from pedestrian and motor traffic.
Like native plants, native trees provide deep roots that take in water and help it seep into the ground. They also catch falling rainwater, keep the creek cooler, provide shade for communities, and capture carbon from the atmosphere.
There are multiple perspectives on how to mitigate these issues
- Plant trees in large concrete boxes covered with metal grates—this method protects trees from the impacts of soil compaction and provides a steadier water supply but can limit root growth
- Plant trees in open spaces with plenty of room for root growth—this method gives more space for maturation but does little to prevent compaction
- Run pipes between trees underground—this method provides trees with more space and consistent access to water but doesn't prevent trampling over root systems
- Plant trees in depressed areas surrounded by other native plants—this method provides trees with space for maturation and provides some protection against compaction and water supplyBecause of their size and deep root systems, trees are especially adept at infiltrating surface runoff and improving water and air quality. Unfortunately, most urban trees do not survive long enough to meet their full potential environmental impact (Minnesota Stormwater Manual 2017). This is largely due to limited space for root growth, lack of access to water, and soil compaction from pedestrian and motor traffic.
Like native plants, native trees provide deep roots that take in water and help it seep into the ground. They also catch falling rainwater, keep the creek cooler, provide shade for communities, and capture carbon from the atmosphere.
Volume Reduction/Infiltration
Trees are able to effectively infiltrate water from a quarter acre of surrounding impervious surfaces
Water Quality Improvement
Just one tree can have incredible impact on the quality of surface runoff from the drainage area (Pioneer Valley Planning Commission 2009).
Phosphorus: 74% reduction
Nitrogen: 68% reduction
Total Suspended Solids (TSS): 85% reduction
Air Quality Improvement:
A typical urban tree sequesters about 50 pounds of carbon per year (Minnesota Stormwater Manual 2022).
Biodiversity/Habitat:
Like other native plants, trees provide habitat for native birds and pollinators. They also create patches of native biodiversity in the urban landscape.
How much do Tree Boxes Cost?
A normal street tree will cost around $300–500 to install.
Tree boxes tend to cost around $12,500.
How are Trees and Tree Boxes Maintained?
Especially in the first few months after installation, trees need to be regularly watered. Once native trees are established, however, they can typically do well with minimal maintenance. Urban trees do tend to have shorter lifespans and will likely need to be replaced every 20-30 years.
A concrete Tree Box will need to be replaced every 50 years.
Additional Information
- Fact Sheet for Tree Trenches and Tree Boxes (Minnesota Stormwater Manual 2017)
- Green Infrastructure Practices: Tree Boxes (Rector 2013)
- Low Impact Development Manual for Michigan (SEMCOG 2008)