Tour Green Infrastructure at the Reservoirs

Take a self-guided tour along the shoreline of Griggs, O'Shaughnessy & Hoover Reservoirs to learn about the green infrastructure on site.

Park visitors will see a variety of methods used to capture and treat stormwater flowing from nearby neighborhoods and roadways. Examples of rain gardens, pervious (porous) pavement, shoreline stabilization and more can be seen and will inspire residents to consider similar projects for their own home.

A healthy, plentiful water supply and quality drinking water begins by protecting water at its source. Green infrastructure offers promising solutions to help remove contaminants from storm water before it reaches our water supply. It is designed to capture surface water runoff. Once detained, pollutants can settle out and filter through pervious surfaces and plants can absorb excess nutrients.

When our landscapes allow stormwater to slow down and soak into the ground, many pollutants will filter out naturally. In addition, by slowing the flow and volume of stormwater, we can reduce stream bank damage, sedimentation and erosion. The result is cleaner water entering our rivers, streams and reservoirs and a more healthy environment for everyone.

Columbus' Watershed Management Program
A high quality water supply source allows us to provide Columbus area residents with excellent drinking water at a reasonable cost. Our watershed program's focus is to protect our drinking water source and supply.

Protecting Our Watershed

We All Have A Hand in Water Protection - Highlights benefits of a clean watershed & smart choices we can all make to have a positive impact on water quality.

View the sign placed at Hoover Reservoir(PDF, 949KB) or Griggs(PDF, 949KB)

Benefits of Watershed Protection Include:

  • Clean rivers for recreation
  • Erosion control & pollution prevention
  • Quality drinking water sources
  • Healthy streams & habitat for plants & animals

Protect Water Resources by Making Smart Choices:

  • Protect wetlands & other vital habitats
  • Manage nutrients & prevent contaminated runoff
  • Protect streams with healthy, natural buffers
  • Avoid development in floodplains
  • Minimize the use of lawn & garden chemicals
  • Wash vehicles in areas designed to capture detergents
  • Keep storm drains free from litter & pollution

Visit Keep It Clean to learn more simple steps you can take at home to prevent water pollution.

Rain Gardens

Slow Down, Soak In & Clean Up Stormwater - Naturally
View the Rain Gardens(PDF, 2MB) signage placed at Griggs & Hoover Reservoirs

Home Rain Garden IllustrationHow Do They Work?
When it rains, a rain garden acts as a basin to capture and absorb water runoff. See larger Rain Garden illustration(PDF, 2MB).

Nutrients, oils and other pollutants are then filtered by the soil and plants.

Deep roots and pervious soils help to slow stormwater's flow, filtering out pollutants and keeping surface & ground water cleaner.

Water Fact: Did You Know?
Rain gardens absorb 30% more water than the same size area of turfgrass.

Backyard BouquetPlant A Beneficial Bouquet of Natives
Ohio-native plants have deep root systems and tolerate drought. This means less maintenance & watering. They also provide wildlife habitat. See larger illustration with labeled flowers(PDF, 2MB).

Sow the Seeds, Reap the Benefits
Plant a rain garden in your yard to protect water quality and:

  • Reduce lawn maintenance
  • Minimize area flooding
  • Recharge groundwater

Shoreline Stabilization

Sedimentation & habitat loss are Ohio's leading causes of water quality degradation. Shoreline stabilization minimizes erosion & protects water quality.

Shoreline Stabilization Minimizes Erosion & Protects Water Quality
View the Shoreline signage(PDF, 1MB) installed at the reservoirs.

Erosion is one of nature's most destructive forces. Through the actions of wind and water, valuable acres of crop land, beaches, streambanks, and shorelines are worn away and lost each year.

The shorelines around Hoover Reservoir contain easily erodible soil types. Left unchecked, erosion reduces available parkland and generates silt and sediments which degrade water quality and harm aquatic life.

Land can be protected from erosion with the use of natural and engineered solutions.
Examples include willow plantings (photos), A-jacks®, rip-rap and more. For more photos, illustrations & information, view the Shoreline signage(PDF, 1MB).

Willows establish a fast growing, deep-rooted buffer at the water's edge. Images show an eroded shoreline ready for a willow planting and a mature willow shoreline.

A-jacks® stabilize severe bank erosion while allowing interspersed plant growth for added protection. Rip-rap is ideal for protecting large areas of shoreline.

Willow Plot Willows

How You Can Help Minimize Erosion:

  • Landscape with deep-rooted, native plants
  • Prevent boat wakes which damage shorelines
  • Avoid creating areas of bare soil, including paths
  • Plant a buffer of trees or shrubs along the water's edge instead of turfgrass.

A-jacks® stabilize severe bank erosion while allowing interspersed plant growth for added protection. Rip-rap is ideal for protecting large areas of shoreline.

A-Jack Installation A-Jack

Pervious Pavement

Pervious Pavement Slows Down, Soaks In & Cleans Up Stormwater - Naturally. Watershed health begins to decline with 10% impervious (non-porous) surface; 30% coverage causes severe impairment.

Slows Down, Soaks In & Cleans Up Stormwater Naturally

View the Pervious Pavement(PDF, 1MB) signage installed at the reservoirs.

Rainfall and melting snow carry oils, sediments and other pollutants from impervious (non-porous) surfaces such as buildings, sidewalks, roads, driveways, parking lots and rooftops to nearly waterways.

One way to lessen the impact on our rivers and streams is to reduce the amount of impervious surface. Many alternatives provide a hard surface while allowing water to filter through and reach the underlying soil where pollutants can filter out naturally.

A parking lot (illustrated below) featuring pervious concrete and pavers, can be designed so that regular asphalt drains towards the pervious sections, where pollutants can filter into the ground.

Water Fact: Did You Know?
Watershed health begins to decline with 10% impervious surface. 30% impervious cover shows severe impairment.

Benefits Include:

  • Improves water quality
  • Melts snow & drains faster
  • Recharges groundwater
  • Reduces heat-island effects
  • Lessens downstream flooding & stream bank erosion

Vegetated Swales

Bioswales Intercept & Treat Surface Water Runoff Urbanization & increases in impervious cover are significant threats to the protection of high-quality drinking water sources & aquatic habitats.

Intercept & Treat Surface Water Runoff
View the Vegatated Swales(PDF, 976KB) signage placed at the reservoirs.

How Do They Work?
Vegetated swales (also known as bioswales or biofilters) are sloped, low-lying areas designed to capture and treat storm water.

The swales collect stormwater runoff and allow it to soak into the ground at a slower rate.

Specialized native plants then help treat the stormwater by absorbing pollutants and filtering suspended sediments. This improves the quality of the surface water that enters the reservoir (or other bodies of water).

Bioswale Cross-section illustration below, or view the Vegetated Swales signage(PDF, 976KB) for a more detailed diagram and description of the process.

Bioswale Detail

You Can Work with Nature to Protect Stormwater:

  1. Keep it Cleaner
    • Hand pull or spot treat weeds to minimize chemical use
    • Replace high-maintenance turf grass with native perennials
    • Dispose of yard waster properly, never in a storm drain or stream
    • Keep oil, dirt, detergents and pesticides from entering storm drains
  2. Reduce the Flow
    • Minimize the use of impervious or hard, non-porous surfaces
    • Maintain healthy vegetative buffers around waterways
    • Use rain barrels, rain gardens & bioswales to capture rain water

Great Blue Lobelia Liatrus or Prairie Blazing Star Cardinal Flower

Native plants such as (left to right) the Great Blue Lobelia, Prairie Blazing Star (or Liatrus), and the Cardinal Flower work to filter contaminants from stormwater when used in bioswales and rain gardens.

Bioretention Systems

Collect & Filter Stormwater Runoff.

Bioretention Systems Collect & Filter Stormwater Runoff
View the Bioretention Systems signage(PDF, 2MB) placed at the reservoirs.

How Do They Work?

Illustrated below, bioretention systems treat stormwater naturally by collecting runoff, allowing it to absorb into the ground at a slower rate, and reducing peak runoff volumes.

Specialized native plants take in excess nutrients and filter out suspended sediments, improving the quality of surface water entering the reservoir (or other bodies of water).

You Can Help Protect Stormwater

  • Minimize use of hard & paved surfaces
  • Use rain barrels, rain gardens & bioswales to capture the flow
  • Maintain healthy vegetated buffers around waterways
  • Keep oil, dirt, detergents, lawn chemical
  • Visit 'Keep it Clean' to learn more

Map 120 AcresIllustrations:

A 3/4" rainfall in this 120 acre area near Griggs Reservoir (map) can amount to 1.22 million gallons of stormwater.

The stormwater flowing from the surrounding neighborhood enters the bioretention basins through an outflow pipe (photo).

Outflow PipeIt then drains into 4 bioretention basins illustrated below.

For a more detailed view and additional illustrations, view the Bioretention systems signage(PDF, 2MB).