1. Upper Malletts Creek
Stormwater Conveyance Study
Project Update
September 30, 2013

2. Meeting Purpose
• Discussion of project recommendations
• Gather public feedback
Items to Review and Discuss
• Alternatives
▫ Review alternative selection process
▫ Present modeling results and recommendations
• Discussion
• Next step – Final Report and City Council
Presentation

3. Project Goals
• Reduce probability of flooding by improving
stormwater management
• Identify cost of implementation per level of service
• Do not adversely impact downstream interests
• Maintain and/or enhance water quality
• Long term sustainability

4. Available Information
• Website
▫ Online at www.uppermallettsstudy.org
• Online Flood Reporting Tool

5. Original Alternatives

6. Alternative Development

7. Areas Outside of City Boundary
Ice Cube
Medium
Meadowinds Basin
Low
X
X
X
2
3
4
X
X
X
X
X
X
5
6
X
X
Alternative Package 7
Alternative Package 5
Alternative Package 6
Alternative Package 4
X
X
X
X
X
X
X
X
1
Low
Low
Alternative Package 3
High
Medium
High
Low
Low
Medium
Low
Alternative Package 2
High
High
Medium
Low
Low
Low
Low
Alternative Package 1
Expected Cost
Name
Lawton Park
Eisenhower Park
Lans Basin
Pioneer HS (W of 7th)
Pioneer HS (E of 7th)
Cardinal Homes
Las Vegas
Impact Potential
Alternative Packages
X
X
X
X
X
X
X
7

8. Flooding Map – March 15, 2012

9. Eisenhower/Churchill Park
Initial Volume (cu. ft) 425,000
Conceptual Volume
390,000
Surface Area (acres)
1.9
Anticipated Costs
$1,250,000
Drainage Area

10. Flooding Map – Post Eisenhower

11. Pioneer/Scio Church Improvements
Drainage Area
Initial Volume (cu. ft) 80,000
Conceptual Volume
400,000
Surface Area (acres)
2.8
Anticipated Costs
$1,000,000

12. Flooding Map – Post Pioneer

13. Lawton Park
Initial Volume (cu. ft) 825,000
Conceptual Volume
340,000
Surface Area (acres)
1.4
Anticipated Costs
$4,500,000
Drainage Area

14. Flooding Map – Post Lawton

15. Volume Comparison
Location
Lawton Park
Eisenhower Park
Pioneer (E. of 7th)
Total
Original Est.
Volume
Conceptual
Volume
825,000
340,000
425,000
390,000
80,000
400,000
1,330,000
1,130,000

16. Footing drain analysis
•
•
•
•
Measured flow approximately 5 gallons per minute
Study using conservative flow of 10 gpm
Total system flow is 483 cubic feet per second
Total footing drain flow is 28 cfs
Footing Drain Flow as Percentage
Of Overall System Flow
5.8%
94.2%

17. Footing drain analysis
Footing Drain Flow as Percentage
Of Eisenhower Basin Flow
Footing Drain Flow as Percentage
Of Lawton Basin Flow
2.2%
5.4%
97.8%
94.6%
No flow attributed to Pioneer basin due to drainage area specifics

18. Discussion

19. Next Steps
• Prepare report
• Presentation to Ann Arbor City Council

20. Upper Malletts Creek Stormwater Conveyance Study Timeline
Public Engagement
Preliminary
Alternatives
Analysis &
Memo
Finalized
Alternatives
Analysis &
Memo
February 2014
Final Study
Report
January 2014
September 2013
July 2013
April 2013
March 2013
February 2013
Data
Collection, Monitorin
g, & Modeling
Project Award
January 2013
Draft
Study
Report
December 2013
Gather
Information

21. Upper Malletts Creek
Stormwater Conveyance Study
Project Update
September 30, 2013