Drainage District and Drain Route Drainage District = 476 acres 316 - - PDF document

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ORCHARD PARK INTERCOUNTY DRAIN

LIVINGSTON AND GENESEE COUNTIES

Meeting to Determine Necessity

Preliminary Engineering Update April 11, 2018 1

Project History

No established drain within drainage district currently Petitioned to establish drainage district filed with Livingston

County Drain Commissioner in September 2015

Determined practical by Drain Board - May 2016 Draft Preliminary Engineering Report - January 2017 Engineer evaluated additional scenarios in 2017 Level of Service and Cost-Benefit analysis Updated route was established on the main drain Petition to establish and construct drain received by LCDC on

January 31, 2018

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Drainage District and Drain Route

Drainage District = 476 acres

• 316 acres-Genesee County
• 160 acres-Livingston County

The Main Drain route was

updated to align with parcel boundaries on January 9, 2018 (6,100 feet)

East Branch provides outlet from

existing retention basin (3,230 feet)

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Orchard Park Retention Basin Flooding Frequency

In last 10 years, the basin flooded 4

times

Also, near flooding in 5/2015 and

5/2016

Photo taken May 2014 by Craig Saddler

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Updated Design Scenarios

In February 2017, additional scenarios were performed for the enclosed portion of the East

Branch

Scenario 1 was included in the Draft Report Scenarios 2 and 3 reduce the pipe sizes but the max HGL would increase Scenario 4 reduces level of service and project costs

Scenario No. Design Storm Maximum Allowable HGL (feet) Basin Outlet Diameter (feet) Max HGL (feet) Drain Time (hrs) 1 25-year 898.5 3 898.4 6 2 25-year 901 2 899 15 3 25-year 901 1.5 899.27 30 4 10-year 898.5 2 898.08 12

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Easements

Estimated 25 easements required Final drain route and project

schedule to be impacted by easement acquisition

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Next Steps (if deemed necessary)

Finalize Preliminary Engineering Report Obtain additional field survey Complete Preliminary Plans Draft easement documents and acquire easements Finalize Construction Plans, obtain permits Issue Bid Documents

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