Design sequence flow chart

This is intended to take you through a design sequence that allows you to determine the appropriate performance goal at a site. Follow the questions below sequentially to arrive at a performance goal appropriate for your site.

DO NOT SCROLL AROUND ON THIS PAGE.

READ THE ALERT BOX BELOW.

Information: INFORMATION ON USING THE FLOW CHART SEQUENCE:

• when you click on an answer (Yes or No), the next question in the sequence will be at the top of the page.
• if a decision point is reached (a performance goal or FTO is determined), there will be a blue alert box and a message saying you have completed the flow chart sequence.
• solid lines separate different questions in the sequence. Remember the next question in your sequence is at the top of the page.

Preliminary information

Prior to using the flow chart, gather the following preliminary information.

• Conduct site review
• Define performance goal

Conduct site review

• Aerial photos and topographic maps
• County soil surveys and other soil information as available
• County Geologic Atlas
• Local groundwater levels
• DWSMA and Wellhead Protection maps
• FEMA and local floodplain maps
• Soil borings and site survey
• MPCA listing of potentially contaminated sites
• Phase 1 and 2 Environmental Site Assessments
• TMDLs and local water quality standards
• Wetland delineations, MNRAM assessments, and wetland classifications
• Proposed conditions, conceptural/preliminary site design
• Local zoning and land use requirements/ordinances, including stormwater rate control requirements
• Communication with local landowners, LGU, or others knowledgeable about the site
• Site inspection

Define treatment goal

• New and redevelopment projects: Retain on site a volume of 1.1 inches from impervious surfaces
• Linear projects: Retain on site the larger of 1.1 inches from all new impervious surfaces or 0.55 inches from all new and fully reconstructed impervious surfaces

Begin Flow chart

Does the project create one acre or more of new and/or fully reconstructed impervious surfaces?

• No
• Yes

MIDS performance goal does not apply

Information: The MIDS performance goal does not apply

YOU HAVE COMPLETED THE FLOW CHART
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Is the project linear?

• Yes
• No

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Are there constraints due to lack of available ROW, off site drainage and/or rate control requirements?

• Yes
• No

_________________________________________________________

Can a reasonable effort to acquire all of the ROW be accomplished?

• Yes
• No

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Is FTO Alternative Number 2 feasible?

• Yes
• No

_________________________________________________________

Select FTO Alternative 2 (linear projects)

Information: Select FTO Alternative 2. Provide documentation of off-site run-on to project area. Provide documentation of lack of ROW

YOU HAVE COMPLETED THE FLOW CHART
_________________________________________________________

Select FTO Alternative 3 (linear projects, zoning/land use requirements)

Information: Provide soil survey, maps, regulations, and/or cost estimates documenting that meeting the original performance goal or FTO alternatives is not feasible in addition to other documentation as required by LGU

YOU HAVE COMPLETED THE FLOW CHART
_________________________________________________________

Are there zoning and land use requirements that make the Performance Goal not feasible?

• No

Is the site located in a DWSMA, wellhead protection area, or within 200 feet of a drinking water well?

• Yes
• No

DWSMA1

• Select Flexible Treatment Option
• (FTO) Alternative No. 2
• Revise Treatment Goal
• No infiltration practices allowed
• Provide DWSMA or well location map

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Utilities, structures, land use requirements

Are there existing or proposed utilities, structures, or land use requirements (density, parking, setbacks, etc.) that make the Treatment Goal infeasible or cost prohibitive?

• yes
• no

Utilities1

Is BMP relocation possible?

• Karst, shallow groundwater, shallow bedrock|yes
• Utilities2|no

Utilities2

Are Flexible Treatment Option Alternatives number 1 or number 2 feasible?

• yes
• no

Utilities3

Investigate Off-Site Considerations:

1. Banking within watershed with goal of:

• Linear: 0.55 inches over impervious
• Nonlinear: 1.1 inches over impervious

1. Cash as determined by LGU

Provide site survey, maps, regulations, and/or cost estimates documenting infeasibility and cost-prohibitive nature of meeting the original Treatment Goal or FTO Alternatives

END

Utilities4

• Select Flexible Treatment Option Alternative No. 1 or No. 2
• Revise Treatment Goal
• Provide site survey, maps, regulations, and/or cost estimates documenting infeasibility and cost-prohibitive nature of meeting the original Treatment Goal

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