HomeMy WebLinkAboutCouncil Presentation 09-17-2019 - Northwest Drainage StudyNorthwest Marana Drainage Study
Keith Brann, Town Engineer
September 17, 2019
Phase 1 Recap
–“East” model starts with 2009 FEMA
mapping model
–Modified for non-regional storm event
–20ft Grid west of CAP canal and north of
Moore Road
–New “West” model
–Non-regional storm event
–20 ft Grid north of Twin Peaks Road
Study Area
•FY19 CIP project
•Detailed hydraulic study of NW
Marana Existing conditions
–Stakeholder discussion of results
February 2019
–Council Presentation March 2019
•Hydraulic model to be used to
model proposed projects
Northwest Marana Drainage -East side
48 Hour time lapse
Northwest Marana Drainage -West side
Phase 2 –Alternatives analysis
•Review and model major flood control infrastructure previously contemplated
–Barnett Channel
–Marana Road Channel
–Hardin Road Channel
•Model CAP canal near airport for breach scenario/potential LOMR
•Review and model minor problem areas:
–Marana Main street
–Various dip crossings
Barnett Channel –Cost and Benefit Area
Right of way acquisition
Excavation
Road crossings
I-10 improvements
UPRR bridges
Major utilities
Selected armoring
Programming Cost
estimate $30M
Benefitting area
2,700 acres
Marana Channel –Cost and Benefit Area
Right of way Acquisition
Excavation
Road Crossings
Sewer trunkline
Selected armoring
Programming Cost
estimate $12M
Benefitting area
1,500 acres
Hardin vs CMID 10.5 Channel –Cost and Benefit Area
Right of way acquisition
Excavation
Road crossings
Selected armoring
Programming Cost
estimate $10M
Benefitting area
900 acres
Marana Airport –Floodplain Remapping
FEMA required modeling
1.With both
embankments
2.Without both
embankments
3.With only one
embankment failed
Next Steps
•Review results with stakeholders
•Finalize master study reports
•Explore funding alternatives
•Supplemental Services to be considered
–Letter of Map Revision for Marana airport