Green Infrastructure Study

Last Updated: 07/01/2020

Latest Update

6/11/2020:
The June 10 virtual public information meeting recording was posted. Watch here.
View the June 10 presentation slides.
Also, see the latest press release about the reimbursement program for residents in the pilot project location.

Project Overview

The City of Madison, like many communities, has experienced an increase in extreme rain events leading to urban flash flooding and lake flooding events. These events have occurred most notably in Madison since 2016, when a large and intense rain event in late July caused extensive flooding of public and private property on Madison’s west side.  Additionally, large events in July 2017 and June 2018 caused similar flooding, again largely on Madison’s west side.

In response to the damage incurred due to recent extreme rainfall events, as well as, the likely increasing frequency of such events due to global climate change, the Madison Common Council authorized the City of Madison Engineering Division to develop watershed models and plans for watersheds of greatest concern in the Madison area. Additionally, the city has initiated a campaign to minimize stormwater runoff entering storm drains through implementation of Green Infrastructure (GI) practices.

Although much is known on the stormwater volume reduction benefits of individual GI practices, very little is known about the watershed response to a collection of practices. The United States Geological Survey (USGS) will facilitate a basic data collection program for the City of Madison, and aims to answer the following questions:

  • How much effective impervious cover (sidewalk, pavement, driveways, roofs etc.) needs to be converted to pervious cover (allows stormwater to soak into the ground) before a reduction in volume can be measured in downstream pipes?
  • Can a waterbody impaired by urban land use (current neighborhoods) ever be able to revert to pre-settlement conditions (oak-savannah) through implementation of GI alone?
  • What temporal scale should municipal officials expect when developing plans for watershed and ecosystem restoration?
  • Are flood models that include large amounts of GI accurate or misleading towards long-term watershed health?

Implementation of Green Infrastructure

The City of Madison will be working to install GI in the study area from 2020-2025. This may include, but is not limited to:

Map showing GI Pilot Area. The study is approximately bounded by the SW Bike Path, Mineral Point Rd, S Midvale Blvd, and Glenway St.


The Toepfer, Holly, Euclid and St Clair street reconstruction project that will be under construction this year is a great opportunity for the City to begin installing green infrastructure within the right-of-way.

On this street reconstruction project, the following GI additions will be included:

  •  Pervious Pavement on the south side of Euclid Ave and St Clair St (this will allow stormwater to soak into the ground instead of flowing directly into a storm sewer).
  • Stormwater Terraces: selected based on which terraces (grass area between the sidewalk and the road) had at least a 15’ wide section of the terrace that would be at least 15’ away from a tree that is not planned to be removed.  There are different options for stormwater terraces, and the treatments are rated as a bronze, silver or gold treatment, depending on the anticipated impact of the treatment.   All Stormwater Terraces will help improve water quality in the lakes, as well as reduce flooding.
    • Terraces that meet the space requirements will default to being a Rain Basin-Bronze, which does not entail extra maintenance on the part of home owner. You may upgrade to a Rain Garden option, which is deeper and has special soil added to the terrace to improve infiltration. You have the option to upgrade to another tier of Stormwater Terrace, including silver or gold options for either a Rain Garden or Rain Basin. The options increase in tier based on their vegetation and therefore infiltration impact:
      • Bronze: Composed of turf grass—basin holds water to allow for infiltration rather than directing terrace/sidewalk runoff or snowmelt into storm sewer. Can be maintained with a standard lawn mower.
      • Silver: Composed of low mow turf grass, low mow turf grass with wildflowers for pollinators, or native sedges. Deeper rooted than turf grass to help encourage faster infiltration and provide some pollinator habitat. Can be mowed with standard mower on high setting, yet only requires mowing once per year in the fall.
      • Gold: Composed of deep‐rooted native grasses and wildflowers to encourage infiltration and provide pollinator habitat. Weeding, as desired, will be the typical maintenance. Plant selections are available on City Engineering’s Rain Garden website.
    • Any upgrades need to be selected before construction begins, and some options will cost the homeowner $100 (see flier). Home owners will also need to maintain the rain garden plantings once installed.  Once construction begins, it will not be possible to upgrade from a Rain Basin to a Rain Garden. Homeowners who will have a Stormwater Terrace on their terrace received notification on 3/16/2020.
    • Learn more with the Stormwater Terrace info sheet.
  • Rock Cribs: sited in suitable terraces to infiltrate driveway and sidewalk stormwater runoff. These include pervious pavement and a buried section of rocks with grass over the top.
    • The sidewalk panels between your driveway and the street will be replaced with pervious sidewalk panels. Additionally, a portion of your terrace will have a 5 foot wide by 3 foot deep rock crib installed. A foot of topsoil will be placed on top of the rock crib and it will be restored to turf grass. From a visual and maintenance perspective, the terrace will look nearly the same and a home owner can choose to either plant flowers, as long as they conform to terrace planting guidance, or maintain it as turf grass. The pervious panels will function better if annual vacuuming maintenance is done, however this is not a requirement. The terraces will help improve water quality in the lakes as well as reduce flooding. There is no cost to the homeowner for the installation of this device.
    • Learn more with the Rock Crib info sheet.

The street reconstruction expects to be complete by winter of 2020 with the green infrastructure practices being installed after completion of the street resurfacing.

Areas where GI will be located in Street Reconstruction project
Locations where GI will be installed with street reconstruction project.


Additionally, In the future, the City will be working with property owners to install GI, like rain gardens, rain barrels, redirecting downspouts off of impervious areas and native landscaping on their property. The City will hold a separate public meeting on this in the future once more details are available.

Monitoring Equipment

You will notice the monitoring equipment in three locations within the watershed. These locations are subject to change, but will be updated on the website.  They are currently located:

  • On St Clair Street near Westmorland Park
  • On Glen Drive near Glenwood Children’s Park
  • Off the bike path between Odana Road and Briar Hill Road
Typical monitoring shelter
Typical USGS monitoring shelter

You can view the data being collected by the USGS in real time:

Resident Reimbursement for Green Infrastructure in the Green Infrastructure Study Area

To promote the installation of green infrastructure on private property, the City of Madison is reimbursing residents for green infrastructure that they install on their property only in the pilot study area that meet the following criteria:

Criteria for Reimbursement

  1. Green infrastructure shall be of a type approved by this policy which includes:

    1. Rain gardens having a minimum of one downspout directed to them and a minimum of 600 Square feet of impervious as part of the contributing area
    2. Pervious pavement - constructed in accord with the WDNR Standards Oversite Council (SOC) standard *
    3. Green roofs*
    4. Infiltration trenches*
    5. Rain barrels or downspout rain garden
    6. Other practices individually approved by the City Engineer
  2. Green infrastructure shall have a design approved by the City Engineer prior to commencement of construction to be eligible for this program. Planting plans will be approved by the City Engineer prior to the purchase of the materials.
    1. Please email your design to Richie Breidenbach at rbreidenbach@cityofmadison.com
    2. Plants on City of Madison Rain Garden website’s planting plans do not need pre-approval. Plants not on the Rain Garden website shall be pre-approved.
    3. An example will be posted soon.
    4. A design checklist to help you avoid typical design issues will be posted soon
    5. * these types of green infrastructure elements tend to pair with major house or landscaping renovations and vary in design. Please consult with the City, via Richie Breidenbach, before planning to receive City reimbursement for these types of green infrastructure.
  3. Green infrastructure that is landscaping or construction-based (Rain garden, pervious pavement, green roof, infiltration trenches) shall have a deed restriction signed, submitted to, approved by the City Engineer and recorded with the Dane Co. Register of Deeds prior to reimbursement.
    1. The deed restriction shall require that the green infrastructure remain in place for a minimum of five (5) years and that the property owner maintain same in good condition during that time period. This deed restriction will ‘run with the land’ if the property sells.
    2. This is not required for rain barrels.
    3. Draft deed restriction language will be posted soon
    4. Once signed, the City will submit and pay for deed restriction
  4. The green infrastructure installation shall comply with all relevant City Building Inspection Codes
    1. A relevant building code cheat sheet will be posted soon.
  5. The resident shall submit time stamped before and after pictures of the installation area to City Engineering at time of the reimbursement request.
    1. Typically this is automatically stored in the info or properties of photos taken on your phone and should send automatically via email.
  6. The property owner shall submit proof of payment or contractor bill within 90 days after completion of work. In instances where the property owner is unable to pay the contractor due to lack of available funds, the payment on behalf of property owner to the contractor can be coordinated by City Engineering with the City issuing a check to both the property owner and the contractor.
    1. Proof of payment includes signed receipts, invoices, etc.
    2. Please submit your proof of payment to: Richie Breidenbach at rbreidenbach@cityofmadison.com
  7. If the property owner is doing the installation without hiring a contractor, all documented costs will be reimbursed as outlined below.

Items Not Reimbursed by the City of Madison

The installation of landscaping including plants, trees, and shrubs outside of the green infrastructure area identified on the approved plan. A three foot wide path from down spout to the garden and a 3 foot buffer around the top of the garden is the maximum area allowed for the green infrastructure foot print unless pre-approved.

Reimbursement Rates

  • For approved green infrastructure constructed by a Contractor, the Stormwater Utility shall reimburse 80% of expenditures up to a maximum of $1,000.00.
  • For approved green infrastructure constructed by the homeowner, the Stormwater Utility shall reimburse as follows:
    • Provided all work is completed by the property owner or by means other than a hired contractor, 110% of documentable expenses up to a maximum of $1,000.00.
    • Labor provided by the property owner shall not be directly compensated.
    • If the property owner completes the majority of the work but excess material is hauled off by City Engineering staff, reimbursement shall be 90% of documentable expenses up to a maximum of $1,000.00.
  • Additionally, residents who have installed green infrastructure may be eligible for credits on their Stormwater Utility bill. To do so: Submit the completed Stormwater Utility Credit form to pgaebler@cityofmadison.com.

Public Involvement

There are a number of points of contact during this project where the public is encouraged to give feedback as part of public information meetings (if applicable to the project), public hearings and collaborations. Dates and times are indicated below:

Public Information Meetings

A virtual public information meeting was held June 10, via Zoom.
June 10 Virtual Public Information Meeting Recording 
June 10 PowerPoint Presentation
Read the full press release: Green Infrastructure, More than a Buzz Word: Pilot, Project, Meeting 

The original public information meeting for this project was scheduled for March 18, but was cancelled due to COVID-19.

Collaborations

  • City Engineering is collaborating with the Friends of Lake Wingra to encourage resident participation in the pilot study. Please take the survey on the Friends of Lake Wingra website to share how we can best support you.