City Engineering offers rain gardens in terraces in conjunction with street reconstructions and resurfacing projects, where they are appropriate. The goal of the Stormwater Terrace Program is to improve water quality by capturing and infiltrating stormwater runoff closer to where it falls and to help residents see stormwater treatment in action.

Streets need to have terraces that meet the following criteria to be considered eligible:

  • Terrace must be at least 10 feet wide from back of curb to edge of sidewalk.
  • There must be at least 15 feet in length available for a rain garden.
  • Trees: excavation for the rain garden can only begin at the drip line or least 15 feet, whichever is less.
  • Driveways and sidewalk ramps need to be at least three feet from edge of rain garden.
  • Property boundaries need to be at least three feet away from the edge of the rain garden.
  • Terraces cannot be too steep (in any direction).
  • The rain garden needs to overflow back into the curb, away from the sidewalk/house.
  • There cannot be issues with high groundwater.
  • Depth to buried gas and or water main if they exist will need to be considered.

If you are unclear as to a site’s suitability, City Engineering staff will do a site visit and make a determination based on the above criteria.

As long as these criteria are met, City Engineering will offer cost-sharing to homeowners who are interested in participating in this volunteer program. We continue to strive to improve and streamline this program each year, and the interest has continued to grow.


Terrace Rain Garden specifications
Terrace Rain Garden specifications

Planting and Maintenance

Once constructed, City Engineering will remove weeds, install native plant plugs, mulch and place sandbags on the curb cut of the homeowner's new rain garden for the first growing season. Homeowners will be able to choose from a wide variety of planting plans featuring native species. The cost to homeowners is $100, which covers their costs for all construction, labor, mulch and plants. Typically, the full cost of these rain gardens is approximately $2,500.

Homeowners may plant the garden on their own. In this case, cost of plants and labor is the responsibility of the homeowner. All maintenance following the initial planting is the responsibility of the homeowner.

Regardless of who plants the garden initially, All maintenance following the initial planting is the responsibility of the homeowner. Plantings must be maintained in accordance with the Terrace Treatment Policy.

Garden Removal

Should a homeowner sell their house or decide that they no longer want a terrace rain garden, the gardens are designed so that they can be filled in by the homeowner and reseeded with turf grass.