Nebraska’s water resources are highly revered not only across the state, but across the country. Nebraska has the most groundwater out of any other state, due to the presence of the Ogallala Aquifer and we’re home to 80,000 miles of rivers and streams. Nebraska also averages about 27 inches of rainfall annually. All of that precipitation has to end up somewhere – it is either absorbed into the soil, or it ends up as runoff. Runoff is described by the Nebraska Department of Transportation (NDOT) as precipitation (water, snow, hail, etc) which travels over impervious, or non-absorbent, surfaces. Examples would be: a city street, sidewalks, or even overly compacted soil. Runoff can be detrimental to an ecosystem because of its ability to pick up pollutants and carry them across long distances or into other bodies of water.
How do we address runoff? This is where stormwater management comes into play. Stormwater management requires community members, businesses, and city officials to use best management practices, or BMPs, to reduce or eliminate the effects of runoff. Typically, rural and natural areas tend to have less impervious surfaces, which in turn means these areas have less of an issue with runoff. Urban areas tend to struggle more with this issue. Typically, a combination of gray (traditional) and green infrastructure is used to address runoff and stormwater.
What is Green Infrastructure?
Green infrastructure refers to the use of plants, permeable or absorbent materials, and intentional design in landscaping in order to reduce the amount of runoff and increase absorption or storage of stormwater. It can be implemented on multiple different scales, ranging from a single household to an entire watershed. These practices come in several different forms that can be integrated into a community.
Here are some common types of green infrastructure practices according to the EPA.
- Downspout Disconnection: Downspout disconnection refers to the practice of allowing your rooftop gutters to drain into a space that absorbs the water, rather than draining into a storm drain. One example of this would be a downspout planter, which, when placed beneath the gutters, utilizes the water for several plants.
- Rainwater Harvesting: Rainwater harvesting is the practice of collecting rainwater in either a rain barrel, cistern, or other containment area to be used later. It can even be reintroduced to an aquifer after its collection.
- Rain Gardens: Rain gardens are groupings of plants and other native and natural features that intentionally mimic a local ecosystem, while also using the elements of art and principles of design to appeal to the human eye. They stop runoff by utilizing native plants and biomimicry (mimicking the ways of nature and its structures).
- Planter Boxes: Planter boxes are typically useful in more urban settings, or places with less space. Similar to rain gardens, they use plants to recapture stormwater, trapping it in the planter box to allow for it to be reabsorbed.
- Bioswales: Bioswales use plants and other natural elements, similar to a rain garden, to redirect and recapture stormwater. They are typically found in narrow natural spaces in urban areas, such as between the sidewalk and road.
- Permeable Pavements: Permeable pavements are useful because they use porous but strong materials that trap water in place, storing it. This prevents both runoff and the buildup of water on top of the road or walkway, which in some cases lead to the build up of ice and water.
- Green Streets and Alleys: Green streets and alleys typically utilize at least one of the above green infrastructure methods in their planning in order to capture and filter stormwater.
- Green Parking: Green parking can employ permeable pavement, planter boxes, and bioswales in otherwise unused parts of the parking structure. Much like green streets, green parking utilizes different green infrastructure practices to make parking lots and structures more efficient.
- Green Roofs: Green roofs are essentially rain gardens which help collect rainwater on top of a building. The cover from the foliage of the plants also helps to aid in cooling for the building itself. These structures typically help those who live in areas which are heavily urban, where there is little to no green space.
- Urban Tree Canopy: The Urban Tree Canopy refers to the network of trees across an area, specifically a city. Trees absorb stormwater, while also slowing runoff and cooling urban areas
- Land Conservation: Protecting natural spaces is key to stormwater management. By protecting these areas, you are protecting a system that was naturally formed to handle local conditions. These areas typically consist of permeable materials, and will naturally direct and absorb stormwater.
Green infrastructure’s diverse forms help cities ranging from large to small in addressing stormwater needs. Diversity is resiliency: the more safety nets you have, the more likely you are to be protected and, in this case, the less runoff is produced.
Green Infrastructure Across Nebraska
Across Nebraska, there is action being taken to manage stormwater. After the March 2019 flood, stormwater, runoff, and flooding is a worry for all Nebraskans. Several cities and towns have taken steps to implement green infrastructure projects.
Tri-cities (Scottsbluff, Gering, Terrytown) Green Infrastructure Program
Tri-City Stormwater serves the towns of Scottsbluff, Gering, and Terrytown, NE. It was founded in 1996, with Scottsbluff serving as the leader in education and outreach. Their green infrastructure project began in Scottsbluff in 2010 with the construction of a rain garden outside of the Scottsbluff Public Safety building. What followed was a beautification plan for downtown Scottsbluff which included parking lot gardens, as well as sidewalk bioswales and tree plantings.
Adaptation is key in these infrastructure programs. Leanne Sato with Tri-City Stormwater, mentions that maintenance can be an issue for smaller towns and municipalities, citing that staffing and scheduling require attention in regards to this kind of infrastructure. She also emphasizes the need for experts in horticulture and ecology in maintenance. The key is to select plants which are native to the area, or which are already adapted to the climate which you are planting in.
Lied Scottsbluff Public Library Bioswale Tri-City Stormwater’s current vision is for residents to realize that there are ways green infrastructure can be implemented residentially. This project, which was designed by Eagle Scouts, directs stormwater runoff from the library into the bioswale, where plants such as sedges, Joe-Pye-weed, and sumac help absorb it and stop it in its tracks. Whatever the plants cannot absorb is redirected into a drain located inside of the bioswale, where it is treated.
Gering Plaza The city of Gering is also the focus of downtown revitalization. The Gering Plaza, located in downtown Gering, is used as an event space. It simultaneously addresses the community’s recreational needs, as well as its water management needs. Two of the patios used in this plaza are made with permeable pavement, and purposeful landscaping which redirects and filters stormwater. The design combines form and function to create something beautiful, where every piece has a purpose.
Kearney Private-Public Partnership
Located right in the heart of Nebraska, in the Platte River Valley, Kearney highly values its water resources, as well as its community members. This is one of the reasons that it decided to take a unique approach to green infrastructure.
The Kearney Demonstration Rain Garden came to fruition from a public-private partnership between the city of Kearney, Kearney High School, the UNL Extension, and Steinbrink Landscaping. It is located alongside N Railroad St. W, between 30th Ave and La Crosse Dr. This area was chosen because of its location, the fact that it is public land, and the fact that it was already a drainage area. After identifying the area, Rocky Steinbrink worked with the city of Kearney to develop this rain garden as a teaching opportunity, to show the city the value of green infrastructure. This 200-250ft space was planted by high school students, and utilizes plants provided by Steinbrink. It requires little to no maintenance, and will continue to grow and fill out as time goes on.
The use of this public-private partnership not only allows the city to implement better stormwater practices, but also provides the students with a hands-on learning opportunity that helps better their city. It also allows for community members to learn more about their city’s stormwater management plan, and about stormwater in general.
Columbus Chamber Rain Garden
The Columbus Chamber of Commerce Rain Garden is a water-wise garden that also functions as a rain garden. It was funded by the Nebraska Statewide Arboretum’s Waterwise Program, which has been replaced by their Greener Towns program. Water from the building first flows through bioswales located under downspouts, then down into the rain garden itself.
The garden was specifically designed to be both diverse and compact to fit the needs of the community. Its design focuses on functionality, but also beauty and cohesion. They wanted the space to be inviting due to its high traffic, while also displaying the ability of these various native plants to act as stormwater managers. Plants such as Joe Pye Weed and sedges both provide function, due to their excellent ability to both slow and absorb runoff, but also provide beauty and diversity.
UNL East Campus Green Infrastructure
The Veterinary Diagnostic Center on UNL’s East campus is a larger scale project which drains water from the VDC and its parking lot into a bioretention basin (bioretention is the process of removing pollutants and sediment from stormwater runoff). The University of Nebraska Lincoln has a stipulation in its MS4 stormwater plan that requires it to treat the first 4 inches of stormwater. Therefore, when the VDC was redesigned, the bioretention basin was created to work in tandem with the building.
There are small bioswales which start off fairly structured at the front of the building, but become more natural as it moves from the building towards the bioretention basin. The design guides water from the building, through the front part of the garden. Downspouts in the building also redirect water into the basin via cement gutters. The actual basin itself uses an amended soil layer and an aggregate layer (meaning a layer of combined materials) with an underdrain to help slow the absorption of water.
This particular project showcases the ability to integrate green infrastructure into a developed space. The use of both green and gray infrastructure together allow for this project to be extremely successful in retaining water and slowing runoff.
UNO Welcome Center Bioretention Garden
The Welcome Center Bioretention Garden is located on the University of Nebraska at Omaha campus. Completed in 2013, it consists of two separate cells, set up in a ying-yang design. It was designed in conjunction with Big Muddy, the University of Nebraska at Omaha, Steve Rodie, and the city. The garden was even recognized in 2014 by Stormwater Solutions, an internationally recognized magazine centering around sustainable and green infrastructure projects.
The garden areas consist of a diverse set of both native and non-native plants. The design is intended to collect stormwater from the welcome center, as well as surrounding buildings and grassy turf, which does little to absorb stormwater. The plants also serve to beautify the space near the welcome center, and the garden is utilized by students and staff alike.
Green Infrastructure at Home
What green infrastructure projects can you do at home? Each specific city has their own regulations in regards to green infrastructure projects, so always do your research before taking on a project. Easy projects to create at home include rain barrels and downspout planters.
Downspout Planter: Building a downspout planter is another easy way to reduce your runoff at home. This reference guide from Philly Watersheds provides a starting point on how to create a downspout planter.
Bioswales and Rain Gardens: The Nebraska State Arboretum has a list of native plants in Nebraska, as well as a resource for how to design and plant a garden. It also has a list of other projects that you can take inspiration from. This guide from UNL has a list of rain garden plants.
Want to learn more? Here are some more green infrastructure resources!