Creating Residential Rain Gardens

Rain Gardens

A rain garden is a landscaped, depressed area that can hold stormwater runoff from impervious surfaces (such as a street) while it infiltrates into the soil below.

The City of Saint Paul encourages residential rain gardens. Properly designed and well-maintained rain gardens can increase a home’s curb appeal, while improving water quality, and adding habitat. There are already over 400 residential rain gardens in the City. This guide identifies resources for Saint Paul residents interested in creating a rain garden. It also helps property owners understand the City’s permit steps for residential rain garden construction.

Sustainable Saint Paul

The City is taking proactive steps to protect our air, water, and urban landscape by focusing on Carbon Dioxide (CO2) reduction activities in the areas of energy efficiency and conservation, clean energy supply, alternative fuels and transportation options, recycling and waste reduction, urban reforestation and natural resources management, and water resources management.

The City of Saint Paul encourages all residents to contribute to a sustainable urban living environment by installing rain gardens. There are many benefits for using native plants and limiting pesticide use such as sustaining ecosystem pollinators like birds, butterflies, and many beneficial insects which commonly utilize rain gardens.

Saint Paul's Residential Rain Garden Programs

This guide provides instruction for residents to create an independent rain garden on residential private property or the associated public boulevard. The City also offers partnership programs, which are listed below.

Saint Paul Residential Street Construction

Each year, the city reconstructs 10-to-15 miles of residential streets to improve street paving, curbs and gutters, sidewalks, landscaping, and lighting. The City of Saint Paul partners with Watershed Districts to offer boulevard rain garden installations to residents in residential street reconstruction project areas. You must be a resident within a project area to participate in the program.

Inspiring Communities Program (ICP) Partnership

The Inspiring Communities Program is a housing redevelopment strategy. It provides focused investment in cluster areas in neighborhoods most impacted by foreclosure and vacancy. The City partners with Watershed Districts to incorporate rain gardens into the design of rehabilitated homes.

Private Property

Know your property lines. Your rain garden must be on your property. You are responsible to locate all utilities. Call before you dig! Contact Gopher State One Call at (651)-454-0002.

Rain gardens on private property are generally considered minor landscaping improvements. City review or permits are typically not required, unless the following apply. For proposed rain garden installation on private property answer these questions:

1. Does your work involve movement of more than 50 cubic yards of fill, or grading in excess of 10,000 square feet?
2. Do you need retaining walls 4-feet tall or greater to be installed or modified?
3. Is the rain garden edge within 10-feet of a structure?
4. Does runoff or you drainage design direct water towards another property?

If your rain garden on private property is not considered minor landscaping, you will need to obtain a building permit from the DSI plan review counter.

Post-Construction Tips

Rain gardens require care and ongoing attention. You are responsible for any potential impacts resulting from poor rain garden design or inadequate maintenance. Common impacts include safety or nuisance concerns like:

• Plants that will encroach onto the sidewalk, due to height and/or placement
• Plants that create general public safety concerns, or noxious weeds
• Water overflows from the garden, draining onto sidewalks
• Standing water

If a complaint is filed with the City of Saint Paul regarding a rain garden, Code Enforcement will inspect the situation. If changes are required and not corrected, a citation may be issued for a violation of City Code. 

Basic City Permit Process

Private Rain Garden

1. Review Private Property questions above.
2. If you answer “no” to all questions, the rain garden is considered minor landscaping. No permit is needed.
3. If you answer “yes” to any questions on page 3, a permit from DSI is needed.
4. For DSI permit, review site design with DSI Plan Review.

Boulevard Rain Garden

1. Fill out registration form.
2. Submit registration form and plans to Department of Public Works.
3. Receive registration approval letter.
4. Contractor applies for Public Works permits, and other permits as needed, for example, Forestry.

If the property is designated as a Heritage Preservation Site then you will also need approval from the Heritage Preservation Commission or its staff prior to city permits being issued.

Boulevards (Public Right-of-Way)

Boulevard rain gardens that will collect street runoff must be reviewed and approved prior to construction. Residents must register a proposed rain garden with the City by completing the separate Boulevard Rain Garden Registration Form.

Registration Opportunities and Timing

Each year the City provides three opportunities to apply for a registration. These align seasonally with key windows for successful rain garden construction, avoiding heat stress or severe weather associated with midsummer, as well as serve to organize the city’s assistance and review efforts for residents.

• Register by April 1 for early summer construction.
• Register by June 1 for late summer construction.
• Register by August 1 for fall construction.

Expect a minimum of two weeks for staff review

The registration form must have plans attached which must be to-scale and show property lines, utility locations, trees and tree canopy, drainage areas, existing and proposed elevations, and rain leaders , inlets, or other drainage features. Expect a minimum of two weeks for staff review. Other information and details may be requested during staff review. The property owner will receive a registration approval letter.

Requirements

The City does not require the use of standard designs for rain garden features. However, many local laws govern activities and features in the public right-of-way. All conditions stated in relevant city ordinances apply, including:

• Chapter 73 Heritage Preservation Commission
• Chapter 105 Care and Maintenance of Boulevards
• Chapter 116 Right-of-Way Administration
• Chapter 121 Permits for Driveways, Sidewalks, Curbs, etc.
• Chapter 135 Right-of-Way Permits
• Chapter 176 Preservation and Protection of Trees

Staff may deny elements of a proposed plan following review in order to best balance multiple right-of-way needs and boulevard uses. Rain gardens proposed near existing street trees will be reviewed for potential tree impacts, including root systems, and shall be designed to avoid excavation within the drip line or damage to the trees.

Boulevard rain gardens require maintenance but a formal city agreement with a residential property owner is not required.

Approvals and Conditions

Depending on design, several permits may be necessary from different offices. Permits for curb work, excavation, obstruction, and sewer are issued to the contractor. The contractor must provide the registration approval letter and reviewed plan to the Right of Way Permit Desk at the time of excavation permit application. Planting, pruning, or removing trees in the boulevard requires a permit from the City Forester (see contact info below).

Work on curbs, sidewalks and driveways within the right-of-way must be done under a permit from the Sidewalk Office. If your curb work damages the street, pavement restoration (asphalt and concrete) is performed by the Public Works Street Maintenance Division. Your contractor is responsible for payment to the city for your cost of such restoration.

Rain Garden Maintenance

Regular rain garden maintenance will be required for at least the first two years. Once your rain garden becomes more established, the need for maintenance will decrease.

Watering

If newly planted plants do not receive natural rainfall, water them once a week with an inch of water during the first growing season.

Weeding

Lightly weed the rain garden once a month. This will help the new native plants become established, and keep the rain garden looking clean and neat. Leaving plant tags next to the plants will help in determining which plants are desirable. In following years, the weeding should be reduced to just twice a year or as needed if the mulch layer is maintained.

When the perennial plants go dormant in the fall, the plants may be pruned at that time, though it is recommended to prune back the plants in the spring after they have started to green up again. This will help with identification of desirable versus undesirable plants.

Mulch should be added to the rain garden annually or biannually to maintain a layer of mulch at least 3” in depth. This will help reduce the amount of weeding required.

Dead plant material can be removed at any time. Replanting can be done during the growing season, though spring and fall plantings are usually more successful. This will allow more light to reach the new growth, and help with the establishment of the new plants.

Checklist for Boulevard Rain Gardens

Submit a plan with scaled dimensions showing:

• Property lines
• Utility locations (Gopher State One Call)1 (800) 252-1166
• Tree(s) and tree canopy
• Drainage area(s)
• Existing and proposed elevations
• Rain leaders, inlets, drainage features

Contact

Boulevard rain garden plans including name, address, email, and phone number can be submitted to:

Public Works

Mapping & Records

25 West 4th Street

Saint Paul, MN 55102

(651)266-6150

For More Information

Water Agencies

Ramsey Soil & Water Conservation

https://www.ramseycounty.us/residents/environment/soil-water-conservation

(651)266-7270

Capitol Region Watershed District

http://www.capitolregionwd.org/

(651)644-8888

Ramsey-Washington Metro Watershed District

http://www.rwmwd.org/

(651)792-7950

City Departments

Department of Public Works

http://www.stpaul.gov/public-works

(651)266-9700

Department of Safety and Inspections – Building Plan Review

http://www.stpaul.gov/index.aspx?NID=671

(651)266-9007

Department of Parks and Recreation – Forestry

http://www.stpaul.gov/index.aspx?NID=4529

(651)632-5129

Department of Planning and Economic Development–Historic Preservation

http://www.stpaul.gov/hpc

(651)266-9078

City Activities

All boulevards are public property and subject to the right of the City to perform necessary work; plant, trim and otherwise maintain trees; access utilities and store excess snow. In the event the City interferes with boulevard plantings in the course of such work, it is responsible only for restoring the boulevard to the original grassy state with black dirt and grass seed. In no event is the City liable for any damage to, disruption of or removal of plantings, either direct or indirect, as a result of the City, its employees, agents or contractors performing any installation, maintenance or repairs. Further, the City has the right to remove or restrict any plantings deemed to interfere with the safety of pedestrians and motorists.