Nutrient Management in the Urban LandscapeRebecca Kluckhohn, P.E. Watershed Engineer

West Metro Water Alliance Forum, May 18th

2011

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Overview: Urban/ Suburban

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• Why do we care?

• Sources

• Solutions

• Cost vs. Benefit

Why do we care?

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• Water resources• lakes & streams

• Regulations

• MS4s

• TMDL

• People complain

• Level of service

• Budgets

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• Altered hydrology• Dry deposition & wash

off from impervious areas • Urban green space• Pet waste• Urban wildlife

Sources

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• Source: Altered hydrology?

• Solution: Reduce runoff• Reduce impervious

area• Mitigate soil

compaction• Pervious pavement• Green roof• Depressional Storage

Sources…Solution

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• Source: Dry deposition & wash off from impervious areas

Parking lots, driveways, rooftops, sidewalks• Solution: Manage

what comes off of the impervious you do have

• Disconnect them• Street sweeping• Pet waste ordinance• Education

Sources…Solution

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• Source(s): Urban green space• Lawns, leaf litter,

phosphorus fertilizer• Pet waste• Urban wildlife• Degraded wetlands

Solution• Leaf litter ordinance• Pet waste ordinance• Education

Sources…Solution

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• Rain gardens,• Bioretention• Swales• Pervious

pavement• Green roofs• Underground

storage• Cisterns

BMPS: Where to put them?

Understand how to link:

• Cost of design, construction, O&M of stormwater BMPs/ Benefits

• Impact of practices/ BMPs on water quality– target a specific outcome

• Communicate a level of service to constituents

Things to Watch for:

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• Linkage of TMDL goals with MS4 permit requirements/ development requirements– this will most likely be more restrictive than current standards

• Move from design standards to performance standards/ effluent limits

Things to Watch for:

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• Emerging practices

• Water Reclamation & Reuse

• Twins Stadium

• Kimball, MN

• Integrated Functions for Stormwater Infrastructure

• Aesthetic, recreation

• Green Infrastructure

Things to Watch for:

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• Economic Issues: • The need to quantify & communicate

the value of stormwater management • The need for financing (long-term

O&M)• Groundwater impacts

• Climate Change– The intersection of stormwater management and energy management

• Breakdown of the separation between dealing with “storm”water and just dealing with water

Things to Watch Out for:

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• Green Infrastructure vs. Grey Infrastructure Don’t throw the baby out with the bathwater…you typically need both. Grey doesn’t always mean “not green”.• You can’t deal with the 100 year event in a rain

garden• Application of BMPs will always be site specific• Justify costs to keep sustainability sustainable

Opportunities:

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Look for opportunities in your practice for creating visual expressions of stormwater management/ infrastructure to further the cause of water resource protection

Questions?

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