mpca mids update

7/29/2019 Mpca Mids Update

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Minimal Impact Design Standards

MPCA staff - Anne Gelbmann, Bruce

Wilson and Mike Findorff P.E.


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Stormwater Standards and

Credits to Protect WaterQuality

MinimalImpact

DesignStandards

SF 1892

HF 2133Storm water discharges

management standards and

appropriation


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New State Legislation 2009

(c) The agency shall developperformance standards, design standards, or other

tools to enable and promote the implementation oflow-impact development

and other stormwater management techniques. For the purposes of this section,

"low-impact development" means an approach to storm water management

thatmimics a site's natural hydrologyas the landscape is developed. Using the

low-impact development approach, storm water is managed on-site and the

rate and volume of predevelopment storm water reaching receiving waters is

unchanged. The calculation of predevelopment hydrology is based on native soil

and vegetation.

Minnesota Statutes 2009, section 115.03, subdivision 5c


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What is MIDS?

An attempt to bring Low ImpactDevelopment (LID) to the forefront

An effort to standardize benefits of waterquality practices

A tool that can be used to help meet

water quality regulations

A voluntary program


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NaturalWatershed

50%

40%

10%

Typical pre-development conditions:


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UrbanWatershed

15%

30%

55%

Typical post-development conditions


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Stormwater Management

Filtration

InfiltrationConveyance

Storage


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Past practiceshavebeen ineffective at

protecting waterquality in receivingwaters and onlypartially effective in

meeting flood controlrequirements


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Stormwater controlmeasures that harvest,infiltrate, and

evaportranspiratestormwater are criticalto reducing the volumeand pollutant loading

of small storms


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How do youmake this

function likethis?

20-50 ppb TP

300-600 ppb TP


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Low Impact Development(and redevelopment/retrofits)

Conserve Natural

Areas and maintain

natural drainage

patterns Minimize development

impacts

Keep soils healthy

Treat stormwater at the

source
http://localhost/var/www/vids/2HowItWorksSpadingMachine.avihttp://localhost/var/www/vids/2HowItWorksSpadingMachine.avi


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Engineered


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MIDS Workgroup


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Mimimal Impact DesignStandards (MIDS) Project

Performance Goals: for new development andredevelopment

Calculator: standard method of design and creditsfor a wide range of practices

MIDS Ordinance Package: St. Croix MIDSProject


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Grass/Vegetated Swales


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Filter Strips


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Bioretention = Rain Garden


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Permeable Pavement


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Other Considerations

Integrate MIDS process with State StormwaterManual Update


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Any Questions?

mpca mids update

Documents