Minnesota GreenStep Cities Stormwater Assessment guidance and supporting information

The Minnesota GreenStep Cities Stormwater Assessment, formerly called the Blue Star Assessment, ................

Section One - Planning and Preservation

This section includes four sections that focus on ...........

Section One - Part A: Water Friendly Development Patterns

Images of original St. Paul Ford Plant (left) and proposed development of the Ford Plant site (right). The proposed development includes redevelopment of a Brownfield site, incorporating mixed use, high density development. Image on right courtesy City of St. Paul.

Part A of the assessment includes two sections that address sprawl-limiting strategies and strategies for redevelopment, including Brownfield redevelopment.

Sprawl-limiting strategies

Does your community comprehensive plan allow the following sprawl-limiting strategies? (Select all strategies that apply)

• Mixed-use development (1 pt)
• Compact development (greater than 3 units/acre) (1 pt)
• Transfer of development rights (1 pt)
• Other applicable (1 pt)
• No / I don’t know / not specified (0 pts)

Wikipedia defines urban sprawl as "the expansion of human populations away from central urban areas into low-density, monofunctional and usually car-dependent communities". "Low-density" is an arbitrary term typically defined in local ordinances. Housing densities lower than 1 home per acre are often considered to be low density.

Urban sprawl has many negative environmental impacts, including habitat loss and fragmentation, increased water use, and increased energy consumption. The relationship between urban sprawl and stormwater has not been extensively studied. Sprawl may reduce imperviousness on a per acre basis, but increases overall impervious acreage. High density, mixed-use development, allows for more efficient stormwater management than low density development.

• Mixed-use development: neighborhoods or buildings that include multiple uses, such as residences, shops, restaurants, and businesses. Mixed use development provides more efficient service delivery and results in reduced resource consumption.
• Compact development (greater than 3 units/acre): compact development provides for more efficient delivery of services and resources, resulting in less consumption
• Transfer of development rights: transfer of development rights (TDR), sometimes known as transfer of development credits (TDC), is a market-based tool that allows communities to channel development toward designated growth areas and away from natural areas, drinking water sources and farmland (Smart Growth America).
• Redevelopment of underutilized previously developed sites: underutilized or unused sites (e.g. Brownfields) represent an opportunity to implement mixed use, compact development (discussed above).

Further reading

• The Environmental Impacts of Urban Sprawl
• Environmental Impacts of Urban Growth
• Urban Sprawl
• Benefits of Mixed Use Development
• Compact Development is a Greener Way for American Cities to Grow
• Brownfield Redevelopment as a Strategy for Preventing Urban Sprawl

Redevelopment and Brownfields

Does your community have any of the following incentives specifically targeted to ‘brownfield’ development and redevelopment sites? (Select all that apply)

• Density bonus (1 pt)
• Funding for remediation (1 pt)
• Streamlined permitting (1 pt)
• Reduced impact fees (1 pt)
• Tax increment financing (1 pt)
• No (0 pts)

Green Infrastructure

In your stormwater ordinance is there a definition of green infrastructure -- better management of stormwater while aiming to achieve other environmental, public health, social, and economic benefits? (Select one)

• Yes (1 pt)
• No (0 pts)
• I don’t know / not specified (0 pts)

Climate Adaptation

Does your community have a climate adaptation plan in place to address potential impacts of climate change on community water resource management? (Select one)

• Yes (1 pt)
• No (0 pts)
• I don’t know / not specified (0 pts)

Section One - Part B: Natural Resource Preservation & Management

This section ....

High quality natural resource areas

Does your community comprehensive plan include an inventory of high quality natural resource areas and are land-use decisions guided by the inventory in order to protect these areas from development?

• Yes, a Natural Resource Inventory or Natural Resource Assessment is incorporated into the subdivision or development process (4 pts)
• Yes, inventoried (1 pt)
• No (0 pts)
• I don’t know / not specified (0 pts)

Filling in floodplain areas

Does your community allow filling for development within the floodplain and if so, are restrictions imposed excluding storage of hazardous materials and requiring compensatory storage for fill? (Select one)

• No fill within FEMA and locally defined floodplain allowed (3 pts)
• No fill within FEMA floodplain allowed (2 pts)
• Fill allowed with the above restrictions (1 pts)
• Fill allowed without restrictions (-1 pt)
• I don’t know / not specified (0 pts)

Sensitive wetlands

Does your community protect high quality or sensitive wetlands through a Resource Management Plan or Wetland Management Plan? (Select one)

• Yes, plan exceeds state standards (2 pts)
• Yes, plan meets state standards (1 pts)
• No (0 pts)
• I don’t know / not specified (0 pts)
• Not applicable in my community (N/A)

Buffers

Do your buffer standards include any floodplain, steep slope, vegetation or resource quality considerations? (select all that apply)

• Additional buffer width to encompass 100-year floodplain (1 pt)
• Additional buffer width in areas with slopes 9% or greater (1 pt)
• Buffer language clearly specifies vegetated cover requirements (1 pt)
• Expanded stream buffer requirements for sensitive resources, such as trout streams and/or ORVWs (1 pt)
• No (0 pts)
• I don’t know / not specified (0 pts)
• Not applicable in my community (N/A)

Steep slopes

Does your community have land use protections and/or development restrictions that preserve slopes 18% or greater in a stable, undisturbed vegetated state? (Select one)

• Yes (2 pts)
• No (0 pts)
• I don’t know / not specified (0 pts)
• Not applicable in my community (N/A)

Urban forests

Does your community encourage the establishment and sustainability of urban forests through the following strategies: (select all strategies that apply, then check appropriate score box below)

• Insect & disease control, including ash preservation
• Increased care during establishment
• Increased indigenous diversity
• Tree protection and replacement ordinance
• Design, construction, and maintenance standards for urban forests
• Street reconstruction (including road diet lane conversions) that increases width of boulevard tree right-of-way
• Standards that address soil compaction during and after development/redevelopment of private land, and of public land like street boulevards?
• Stable funding for shade tree program, goals for increasing canopy coverage, or Tree City USA

• At least 5 of the above strategies including soil compaction standards: (8 pts)
• At least 4 of the above strategies including tree program/goals/Tree City: (5 pts)
• At least 4 of the above strategies: (3 pts)
• At least 3 of the above strategies: (2 pts)
• At least 2 of the above strategies: (1 pt)
• None (0 pts)

Section One - Part C: Stormwater Management Funding & Incentives

This section....

Funding mechanism

Does your community have any of the following stable, ongoing, yearly stormwater management funding mechanisms? (Select one)

• Stormwater Utility User Fee (3 pts)
• Other applicable: (3 pts)
• No (0 pts)
• I don’t know / not specified (0 pts)

Incentives

Does your community provide incentives (e.g., a variable stormwater utility fee) for retrofitting stormwater best management practices in previously developed sites? (Select one)

• Yes for commercial, industrial, institutional and residential (3 pts)
• Yes for only commercial, institutional and industrial (2 pts)
• Yes for only residential (1 pts)
• No (0 pts)
• I don’t know / not specified (0 pts)

Land acquisition

Has your community adopted a stable funding mechanism for land acquisition of high quality natural resource and/or riparian buffer areas? (Select one)

• Yes – Land is placed in a trust (5 pts)
• Yes (1 pts)
• No (0 pts)
• I don’t know / not specified (0 pts)

Section Two - Stormwater Management Standards & Practices

This section includes three sections that focus on ...........

Section Two - Part D: Impervious Cover Management

This section....

Impervious surface

Does your community allow proof-of-parking or shared driveways to minimize impervious surface? (Select one)

• Yes (1 pt)
• No (0 pts)
• I don’t know / not specified (0 pts)

Parking restrictions

Does your community utilize any of the following parking lot area restrictions (Select all that apply)

• For retail/shopping areas larger than 10,000 sq. ft. of floor space: 3.3 parking spaces per 1000 sq.ft of gross floor area (2 pts)
• For office buildings: 2.5 parking spaces per 1000 sq. ft. of gross floor area (1pt)
• For transit-oriented development: 1.5 parking spaces per 1000 sq. ft. of gross floor area (1pt)

What is your minimum required office building parking ratio (per 1000 ft2 of gross floor area)? (Select one)

• We have a maximum parking ratio of 3.5 or less (4 pts)
• Fewer than 3.0 parking spaces (3 pts)
• 3.0 to 3.5 parking spaces (2 pts)
• 3.6 to 4.0 parking spaces (1 pt)
• Greater than 4.0 parking spaces (0 pts)
• I don’t know / not specified (0 pts)

What are your standard parking space dimensions (Select one)

• Stalls 8.5' x 18' with 22' maximum aisle and driveway widths (3 pts)
• Stall width 9 feet or less (2 pts)
• 9.1 to 9.9 feet (1 pt)
• Greater than 9.9 feet (0 pts)
• I don’t know / not specified (0 pts)

Vegetated areas

For new residential lots, does your community require or encourage impervious surfaces like roofs and drive ways to drain to vegetated areas? (Select one)

• Required (3 pts)
• Encouraged (1 pts)
• No (0 pts)
• I don’t know / not specified (0 pts)

Vegetated practices

Does your community require or encourage parking area landscaping with vegetated practices (e.g. bioretention, curb-cuts, ribbon curb, tree trenches, or swales) for stormwater volume and/or water quality management? (Select one)

• Required (3 pts)
• Encouraged (1 pts)
• No (0 pts)
• I don’t know / not specified (0 pts)

Pervious/permeable surfaces

Does your community allow & encourage pervious/permeable surfaces on residential/commercial area sidewalks, and residential/commercial parking lots? (select all that apply)

• Yes on residential/commercial sidewalks (1 pt)
• Yes on residential/commercial parking lots (1 pt)
• No (0 pts)
• I don’t know / not specified (0 pts)

Section Two - Part E: Stormwater Management Policies

This section....

New impervious surfaces

For new development, does the permitting agency apply community stormwater management standards to all new impervious surfaces, or is a minimum threshold (de minimis) included? (Select one)

• Standards apply to all new impervious surfaces (10 pts)
• Standards apply to 10,000 sq. ft. or more of new impervious surface (8 pts)
• Standards apply to .5 acres or more of new impervious surface (4 pts)
• Standards apply to 1 acre or more of new impervious surface (1 pt)
• No (0 pts)
• I don’t know / not specified (0 pts)

Rate control

For new development, does the permitting authority apply community stormwater standards requiring rate control based on the difference between a baseline-condition and post-development runoff condition? (Select one)

• Yes, our baseline condition is Pre-European settlement (5 pts)
• Yes, our baseline condition approximates woods/prairie grass in good condition (3 pts)
• Yes, our baseline is pre-development (existing) conditions (1 pt)
• Yes, our baseline is consistent with MIDS (1 pt)
• No (0 pts)
• I don’t know / not specified (0 pts)

Total-suspended solids and total phosphorous

Does your community require best management practices (BMPs) for all new development that will result in at least 90% reduction in total-suspended-solids (TSS) and/or at least 60% reduction in total phosphorous (TP)? (Select one)

• Yes, my community follows MIDS (3 pts)
• Yes (2 pts)
• No (0 pts)
• I don’t know / not specified (0 pts)

Downstream water resources

Are post-construction sediment and nutrient loading requirements customized to downstream water resources, such as critical habitat, impaired waters, ORVW? (Select one)

• Yes (3 pts)
• No (0 pts)
• I don’t know / not specified (0 pts)

Runoff volume

Are there post-construction runoff volume requirements for downstream river erosion protection? (Select one)

• Yes, no runoff volume increase for the 10-yr, 24-hr event (6 pts)
• Yes, no runoff volume increase for the 5-yr, 24-hr event (4 pts)
• Yes, no runoff volume increase for the 2-yr, 24-hr event (2 pts)
• No (0 pts)
• I don’t know / not specified (0 pts)

Erosion and sediment control

(for non-MS4s only) Has your community adopted an erosion and sediment control ordinance that align with MS4 permit requirements? (Select one)

• Yes (10 pts)
• No (0 pts)
• I don’t know / not specified (0 pts)
• Not applicable in my community (am an MS4) (N/A)

Pretreatment

Do your community stormwater management standards specify pretreatment sizing standards for stormwater prior to discharge into all permanent structural best management practices (BMPs)? (Select one)

• Yes (2 pts)
• No (0 pts)
• I don’t know / not specified (0 pts)

Linear projects

Do your community stormwater management standards apply to all redevelopment and reconstruction of linear projects? (Select one)

• Yes, we apply MIDS to all redevelopment (9 pts)
• Yes, reconstructed and net increase in impervious surface (7 pts)
• Yes, net increase in impervious surface only (4 pts)
• No (0 pts)
• I don’t know / not specified (0 pts)

Water conservation

Does your community encourage or require any of the following water conservation strategies: (select all that apply)

• Stormwater water reuse incentives (5 pt)
• Stormwater water reuse standards (3 pt)
• Encourage or require irrigation systems to be retrofitted with Smart irrigation systems that track weather patterns and mitigate unnecessary watering (2 pt)
• Use of low-water vegetation (1 pt)
• Water Conservation Rate Structure that exceeds DNR minimum requirements (1pt)
• Other:___________________________ (1pt)
• No (0 pts)
• I don’t know / not specified (0 pts)

Maintenance agreements

Does your community require & enforce maintenance agreements for privately maintained stormwater facilities? (Select one)

• Yes (3 pts)
• No (0 pts)
• I don’t know / not specified (0 pts)