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PUGET SOUND LID TECHNICAL WORKSHOP SERIES

Site Planning and Infrastructure Jeff Cox, ASLA

Rick Tomkins, PE

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• Site Planning and Infrastructure

• Brief Overview of Site Planning Considerations

• Review of 3 Completed LID Projects

- Site Planning Considerations

- LID Elements

- Infrastructure

- Lessons Learned

• Questions and Answers

Agenda

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Traditional Site Planning Considerations

Project Context: Land Use, Zoning, and Development Regulations, Cultural Constraints

Physical and Natural Constraints

Storm Water Management

Circulation Requirements for Vehicles, Bicycles, and Pedestrians

Utility Availability and Location

Integrating Park and Open Space

Costs

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Additional Considerations for LID Projects

• For LID Projects, the Following Principles Must Be Emphasized Early in the Site Planning Process:

1. Understanding of Development Goals

2. Conserve Natural Areas

3. Minimize Site Disturbance

4. Minimize Impervious Coverage

5. Disconnect Impervious Areas

6. Maintain Site Hydrology

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LID Site Planning Principles

1. Conserve Natural Areas

Protect Sensitive Resources

Cluster Improvements

Retain Trees, Native Vegetation

Create Connected Open Spaces

2. Minimize Site Disturbance

Reduce Disturbance Envelope

Minimize Cuts / Fill

Avoid Site’s More Pervious Areas

Consolidate Construction Activities

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LID Site Planning Principles

3. Minimize Impervious Coverage

Reduce Pavement Width / Sidewalk

Incorporate Permeable Surfacing

Soil Amendments

Green Roofs

4. Disconnect Impervious Areas

Reduce Effective Impervious Area

Minimize Closed Pipe Conveyance

Utilize Multiple Small-Scale Facilities

Dispersion not Point Discharge

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LID Site Planning Principles

5. Maintain Site Hydrology

Reduce Runoff Leaving the Site

Discharge at the Natural Location

Distribute Flows in Sheet Fashion

Provide for Recharge

Promote Drainage Contact w/Soil and Vegetation

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LID and Infrastructure Design

Project Infrastructure Constraints

• Integrate into Existing Built Environment

• Influence of Road Design

• Site Plan Dictates

• Storm Water Management

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Review of Three Completed LID Projects

• Danielson Grove , City of Kirkland

Cottage Company, Ross Chapin

• Kirkland Bungalows, City of Kirkland

CamWest Development, Mithun Partners

• Shamrock Heights, King County

CamWest Development, Dahlin Group

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Danielson Grove

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Danielson Grove

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Danielson Grove

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Danielson Grove

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Danielson Grove

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Danielson Grove

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Danielson Grove

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Danielson Grove

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Danielson Grove

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Danielson Grove

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Danielson Grove

Road Section

Site Plan

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Danielson Grove

Composite Utility Plan

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Danielson Grove

Road and Storm Drainage Plan

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Danielson Grove

Sanitary Sewer and Water Plan

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Lessons Learned

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Kirkland Bungalows

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Kirkland Bungalows

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Kirkland Bungalows

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Kirkland Bungalows

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Kirkland Bungalows

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Kirkland Bungalows

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Kirkland Bungalows

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Alternative Street Section

Low Impact Road Section

Driveway Infiltration Trench Detail Trench to Swale Detail

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Road and Storm Drainage Plan

Kirkland Bungalows

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Water and Sewer Plan

Kirkland Bungalows

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Lessons Learned

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Lessons Learned

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Lessons Learned

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Shamrock Heights, King County

• 34.5 acres

• 25 acres developed

• 73 LID lots

• 129 total # of Lots

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Plan View

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Rain Garden

Rain Garden Section

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Rain Garden

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Rain Garden

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Rain Garden

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Rain Garden

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Rain Garden

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Bioretention Swale

Bioretention Swale Profile

Bioretention Swale Section

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Bioretention Swale

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Bioretention Swale

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Bioretention Swale

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Curb Drop

Grass-Lined Conveyance Swale Low Impact Flow Through Curb

Road Section

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Curb Drop

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Shamrock Heights Monitoring

Sampling Period

Water Quality (Grab Samples at Inlet)

Water Quantity

• Begins at 75% occupancy

• 3 years of data

• Turbidity

• Total Suspended solids

• Dissolved zinc

• Hardness

• Continuous recording of flow at outfall of both ponds

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LID Benefits Realized

• Enhanced water quality

• Relatively high densities achieved

• Reductions in infrastructure footprint and cost

• Differentiation in the market place.

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PUGET SOUND LID TECHNICAL WORKSHOP SERIES

Site Planning and Infrastructure

Questions?