Coffee Creek Park DevelopmentLow Impact Development (LID)

City of Duluth, St. Louis County, MN

February 27, 2008

Presented By:

Christopher J. Rousseau, P.E.

Developer / Owner Information

Trinity Development Group, LLC

Jeffrey Drown

Ted Stocke

Dan Stocke

Location

� City of Duluth, MN – 83.68 Acre Development

North of Trinity Road (TH 53), east of

Anderson Road and south of Quince Street

� Watersheds – Miller Creek to the west and

south west and Coffee Creek to the east

� Adjacent State-Owned Park Land – Homes

have direct access to recreational trails

winding through 175 acres along Coffee Creek

to the east

“In the Middle of Everything…Away From it All”Ted Stocke, Developer

Design Consultant and Partners

MSA Professional Services, Inc. – Planning, Design,

Permitting, and Construction Services

Partners:

EBI – Wetland Delineation

EPC Engineering & Testing – Geotechnical

Alta Survey Company, Inc. – Plat Preparation

Professional Services

� Concept Planning

� Environmental Assessment Worksheet (EAW)

� Environmental Site Assessment (Phase I)

� Alignment Adjustments

� Plat Requirements

� Wetlands Permit / Replacement Plan

� Design and Permitting

� Construction

Concept Planning

� January 2005: MSA worked with Trinity Development Group planning layout concept options (one illustration shown)

Environmental Assessment Worksheet (EAW)

� April 2005: MSA worked with the proposer, Trinity Development Group to present the mandatory EAW, in accordance with EQB (Environmental Quality Board) residential development rule 4410.4300 – 19B to the RGU (Local Government Unit) City of Duluth

Environmental Site Assessment (Phase I)

� August 2005: MSA worked with the Trinity Development Group to conduct an appropriate inquiry into the ownership and use of the property with the goal of identifying recognized environmental conditions present in conformance to ASTM Practice E 1527, including 4 components:

� Records Review – search federal and state environmental

databases

� Site Reconnaissance – visual and physical site inspection

� Interviews – including property owner and local government

officials

� Report – evaluate and document findings, opinions, and

conclusions

� Conclusion: No recognized environmental conditions (RECs) were identified during the assessment

Alignment Adjustments

� Fall 2005 – January 2006: In preparation of working with Alta Survey Company on the plat, MSA worked with Trinity Development Group to collect additional topography information, soil boring logs, and geotechnical data

� With careful consideration given to the existing wetlands, tree inventory, soil conditions, and City of Duluth requirements, MSA revised the concept plan and prepared preliminary cost estimates for the development

Plat Requirements

� January 2006 – July 2006: MSA worked with the Trinity Development Group, neighborhood residents, Alta Survey Company, City of Duluth, St. Louis County, and the wetlands TEP (Technical Evaluation Panel) to determine plat preparation layout design components:

� Avoid and minimize wetland impacts to the maximum extent practicable

� Natural resources conservation (outlots)� 300-foot buffer along the north side of Trinity Road (TH 53)� 200-foot buffer along the east state-owned Coffee Creek area� 50-foot buffers adjacent to existing neighborhoods� Additional easements and outlots as required for wetlands,

utilities, stormwater BMPs (Best Management Practices), and future housing development (senior housing in 2008)

� Perimeter trail system and open park space� R-3 (all residential type) zoning and special use permit for

twin homes (zero lot line setback – shared wall)� Final Plat – 59 Single Family, 54 Twin Homes, and 13 Outlots

Wetlands Permit / Replacement Plan

� May 2006: The Wetland Delineation Report and approved delineated boundary survey determined that the 83.68 acre development contained 15.21 acres of wetland types 2, 3, 6, and 7 associated with large flow through wetlands and isolated depressional wetlands

� MSA worked with the Trinity Development Group to minimize impacted areas to the maximum extent practicable by incorporating:

� Roadway alignment shifting� Roadway side slope gabion / rock retaining structures� Custom lot grading

� The final design proposed impacts of 1.12 acres of wetlands. Under the City’s Water Resources Management Ordinance and the Wetland Conservation Act, impacted wetlands were replaced at a 1:1 ratio on-site

Wetland Disturbance Map

Wetland Mitigation Overview Map

Wetland Replacement Areas #1 - #3

#1

#3#2

Design

� January - October 2006: MSA’s team of technical specialists worked with the Trinity Development Group to provide the following major design development tasks:

� Roadway & right-of-way alignments, profiles, grading� Trinity Road (TH 53) special access tier roadway design� Special retaining structures� Typical section and pavement structure analysis� Utilities – sanitary sewer, water main, and fire protection� Stormwater BMPs (Best Management Practices)� SWPPP (Stormwater Pollution Prevention Plan)� City of Duluth staff meetings and required plan approval

Design

� Roadway & Right-Of-Way Alignments, Profiles & Grading

� Approximately 8,550 lineal feet of 28-foot wide roadway section complete with subsurface drainage, geotextile fabric separation, granular base, aggregate base, concrete curb and gutter, asphalt pavement and adjacent concrete sidewalks per the City of Duluth standards.

Alignment & Grading Plan Sheets

Alignment & Grading Plan Sheets

Alignment & Grading Plan Sheets

Alignment & Grading Plan Sheets

Design

� Trinity Road (TH53) Special Access Tier Roadway

� In order to provide access from the south off Trinity Road (TH53) and avoid wetland impacts, MSA designed a switchback separate lane sections for ingress and egress traffic for Coffee Creek Park development

� On-site blasted granite rock was used to stabilize the inbound roadway side slope to the north

� MSA worked with Gary Hage, P.E. of EPC Engineering and Testing of Duluth. Gary provided design services for the geotechnical global stability analysis on the 1:1.5 (V:H) slope section

Design

� Utilities – Sanitary Sewer, Water Main & Fire Protection

� MSA performed a feasibility analysis and determined that the combination of gravity sewer, low-pressure sewer, lift station, and force main were most cost effective for the Developer and the City of Duluth

� MSA updated the City’s water distribution system model to design water main extension and fire protection requirements for the development

Design

� Low Impact Development Approach to Stormwater Management

� A “Treatment Train” approach is being utilized which is intended to capture and treat storm water runoff at the source.

� By capturing and treating at the source the final BMP storage volume requirements are reduced and time of concentration is increased lowering the peak runoff rates for design storm events.

� No wetland loss on site by avoiding wetland areas and mitigating/replacing impacted wetland areas at other locals on-site.

� Natural resources conservation outlots with development plat

� Stormwater BMPs (Best Management Practices):

� Encourage Homeowners to Use Rain Barrels for Harvesting Rooftopstormwater runoff for filtering and reuse around outside of home

� Homeowners Association Shall Require Homeowners to Install Porous Pavers Driveway Approaches

� Trinity Road Access Median Biofiltration Gallery � (11) Boulevard Rain Garden Biofiltration Practices� (5) Center Cul-De-Sac Biofiltration Basin Practices� (3) Stormwater Management Pond Practices (Wet Pond)� (1) Underground Stormwater Management Filtration Gallery

Design

� Stormwater Design Requirements

� City of Duluth• Dead pool storage volume for 2-½” rainfall event

� Minnesota Pollution Control• Miller Creek is classified as a “special water”trout stream.

o Pending TMDL impairments with temperature and turbidity concerns – biofiltration practices recommended

o Capture and treat 1” WQ runoff (new impervious)• Coffee Creek has no classification for special treatment

o Capture and treat ½” WQ runoff (new impervious)o However MSA designed for 1” WQ runoff

• Flood Control for 10-year and 100-yr storm events• Post <= Pre-Development rates after treatment

� Stormwater BMPs Design Guidance:

� Reference MPCA Stormwater Manual, 2005, Version 1.0• MN Unified Sizing Criteria• Filtration & Bioretention Practices

Trinity Road Access Median Biofiltration Gallery

Rain Garden Biofiltration & Porous Pavers Practices

Center Cul-De-Sac Biofiltration Basin Practices

Wet Ponds & Underground Chambers Filtration Practices

SWPPP (Stormwater Pollution Prevention Plan)

Permits & Approvals

Construction Services

� Shop Drawing Review

� Construction Observation

� Survey

� Construction Staking and Grade Sheets

� Meetings

� Pre-Construction� Construction

� Project Management

� Correspondence� Pay Requests

� Record Drawings

Construction Photos

Homeowners Association (HOA)

� Responsibilities

� Porous Pavers� Biofiltration Galleries/Basins� Rain Gardens� SWM Ponds� Rock Retaining Structures

� Tasks

� Mulch, Plant & Complete BMP’s � Inspection� Operation� Maintenance

� References

� Inspection, Operation & Maintenance Manuals� Final Plans & Specifications

*HOA will complete BMP’s once construction up stream has been completed.

� Engineered media, structures, and piping already installed.� HOA will use local nurseries, landscapers & landscape architects to

select, place, & install native vegetation.

BMPs Inspections, Operations & Maintenance Homeowners Association

BMPs Inspections, Operations & Maintenance Homeowners Association

BMPs Inspections, Operations & Maintenance Homeowners Association

BMPs Inspections, Operations & Maintenance Homeowners Association

Composting Wind Energy

Rain Gardens Rain Barrels

Energy Star Appliances Bicycling & Walking

Solar Power Biofuels

Hybrid Vehicle Wood or Manure Burner

Florescent Light Bulbs Recycling

Water Conservation Carbon Credits

Vehicle Tune-Ups Wearing Clothes >1 Time

Phosphorous-Free Fertilizers Renewable Home Furnishings

Biodegradable Garbage Bags Goodwill Donations

Educating Homeowners to Go “Green”

Coffee Creek Park DevelopmentLow Impact Development (LID)

City of Duluth, St. Louis County, MN

February 27, 2008

Presented By:

Christopher J. Rousseau, P.E.