Green Infrastructure

Runoff from rain or melting snow can affect water quality in nearby streams, rivers, and lakes. Impervious surfaces like roads, parking lots, and buildings prevent runoff from penetrating into soil, leading to flooding and erosion. Runoff also picks up and carries pollutants, pathogens, litter, and sediment to nearby waterways. The resulting water contamination can lead to algae blooms, declining ecosystem health, beach closings, and no-swim advisories.

Traditionally, Michigan communities have managed this stormwater through “grey infrastructure” such as storm drains, sewer pipes, and basins, and other approaches that carry are often expensive and complex. Green infrastructure, however, uses vegetation, soils, and natural processes to capture and slow rainwater or snowmelt as it moves across a landscape. This approach allows water to percolate through the soil and plant roots and can filter out contaminants.

Green infrastructure solutions can be implemented on differing scales. On the local scale, green infrastructure practices include rain gardens, permeable pavement, green roofs, infiltration planters, trees and tree boxes, and rainwater harvesting systems. At the watershed scale, green infrastructure includes preserving and restoring natural landscapes such as forests, wetlands, and riparian buffers along streams. Green infrastructure projects can also help communities improve safety and quality of life, conserve vital ecosystem functions, and mitigate the effects of heavy rainfall and flooding.

PLANNING FOR A SUSTAINABLE FUTURE

One report, Green Infrastructure in Michigan: An Integrated Assessment of Its Use, Barriers, and Opportunities Project, identifies challenges and highlights key initiatives and pilot projects for green infrastructure projects in Michigan. The report, produced by Donald Carpenter of Lawrence Technological University, Sanjiv Sinha from Environmental Consulting & Technology, Inc., and Avik Basu at the University of Michigan, found that barriers to implementation of these projects include conflicting codes and ordinances, cost, lack of financing, maintenance, municipal and public acceptance, lack of regional planning, and uncertainty in performance. The report also discusses how each of these challenges can be overcome. Michigan Sea Granted provided funding for this project. Additional resources from this project are available:

SHORE STABILIZING USING SOFT ENGINEERING

Historically, many river shorelines were stabilized and hardened with concrete and steel to protect developments from flooding and erosion, or to accommodate commercial navigation or industry. Typically, shorelines were developed for a single purpose. Today, there is growing interest in developing shorelines for multiple uses and benefits. Soft engineering is the use of ecological principles and practices to reduce erosion and achieve the stabilization and safety of shorelines while enhancing habitat, improving aesthetics, and saving money.

AT HOME, AT WORK OR IN THE CLASSROOM

Green infrastructure can be a great way to encourage eco-friendly practices at home, at work, or in the classroom. Here are a few steps you can take:

  • Plants are experts at trapping and slowing rainwater and snowmelt. Choose native plants and trees that are adapted to the amount of sun and water your region receives. Put mulch around plants to keep water from evaporating out of the soil.
  • Opt for less lawn. Mowed grass forms a dense surface that makes it harder for water to penetrate into the soil, requiring more water than other types of planting arrangements.
  • Plant rain gardens near downspouts, storm drains, or other low spots where water tends to accumulate.
  • Buy or build a rain barrel. Read how household rain barrels help reduce runoff and lower water bills, and learn how to make and decorate your own rain barrel!
  • Consider installing permeable or porous pavement on your driveway instead of concrete or asphalt.
  • If you live near a pond or lake, leave a strip of plants (called a “riparian buffer”) along the water’s edge.
  • Support local efforts to conserve green spaces, protect wetlands, and add public rain gardens and bioswales.

Regional efforts

Michigan Sea Grant and partners have studied runoff and green infrastructure in west Michigan’s Spring Lake and in southeast Michigan. Find final results from those projects below.