2. Items to Review and Discuss
• Review of study area
• Stormwater management approaches
• Project timeline
• Information collected to date
• Public input
• Discussion
• Next steps
3.
4.
5. Engineering Parameters
• Reduce probability of flooding by enhancing
management of stormwater
• Identify cost of implementation per level of service
• Do not adversely impact downstream interests
• Maintain and/or enhance water quality
• Long term sustainability
7. Catchbasin Enhancements
• Evaluate impact of
installing additional
catchbasins
▫ What is the design
capacity of grates?
▫ Is existing capacity
sufficient?
▫ Will additional
catchbasins provide
significant
improvements?
9. Clean/Repair Existing
Storm Drains
• Identify adequacy of
existing storm drains
▫ Does modeling show drains
to be adequate?
▫ Do public comments
suggest problem with
drain?
• Complete targeted
inspections of storm drains
to establish locations for
repairs and maintenance
10. Enhance Existing Detention
• Review feasibility to
enhance existing detention
▫ Is site acceptable?
▫ Do modeling results show
benefit?
• Evaluate increasing
capacity of basins and
ponds
▫ Sediment removal
▫ Lowering of water levels
▫ Increase surface area
11. Overland Flow Management
• Evaluate changing ground
and street elevations to
enhance overland flow
▫ Map and model
▫ Review pictures and
comments
▫ Complete on sites reviews
▫ Can overland flow be better
managed?
12. New Surface Detention
• Evaluate construction
of new surface
detention facilities
▫ Where is there space
to build?
▫ Will significant
impacts be realized?
▫ Is this space cost
beneficial for
detention?
13. Storm Sewer
Enhancements
• Evaluate installation of
new or larger storm
drains
▫ Modeling and analysis
of storm drain system
▫ What is adequate level
of service?
▫ Where are optimal
and cost effective
locations?
14. Underground Detention
• Identify need for underground detention
▫ Is adequate space for surface detention available?
▫ Is underground detention affordable?
▫ What are groundwater impacts?
15. Bio-retention or Rain Gardens
• Evaluate using in
conjunction with
other management
practices
16. Stormwater Management
Recommendation
• Combination of these management practices
• Other practices may be added
• Cost/benefit considerations will be a factor
• Recommendations must be authorized in City
capital improvement plan and funding secured
• Looking for grant assistance
17. Gather
Information
Public Engagement
Upper Malletts Creek Stormwater Conveyance Study TimelineProjectAward
January2013
April2013
Preliminary
Alternatives
Analysis &
Memo
Draft
Study
Report
Final Study
Report
Finalized
Alternatives
Analysis &
Memo
July2013
December2013
January2014
February2014
March2013
Data
Collection, Monitorin
g, & Modeling
February2013
September2013
18. Information Collected to Date
• Infrastructure records/GIS layers
• Model of the City's stormwater infrastructure
• Past studies and study area maps
• Record of homes where FDD has occurred
• Past soil boring data
• LIDAR information for this area
• Rainfall records from the March 15 2012 storm
• Records/complaints of known flooding
19. Public Input and Engagement
• Public informational meetings
▫ Each 4 to 6 weeks
• Citizens advisory meetings
▫ Each 4 to 6 weeks
• Website
▫ Online at www.uppermallettsstudy.org
• Online Flood Reporting Tool
21. Next Steps
• On-line data collection and web updates
• On-site interviews and data collection
• Catchbasin grate capacity
• March 15 storm event modeling
• Soil boring location evaluation
• Screening of management approaches
• Citizens Advisory Group meeting
• Public informational meeting
▫ 4 to 6 weeks
