Hancock County Flood Diversion

November 10, 2016

Introductions

Steve Wilson, PE, PS

Project Manager

Maumee Watershed Conservancy District

Scott Peyton, PE

Project Manager

Stantec

Outline Project Background

Project Status

Project Future

Discussion

Project BackgroundFindlay

August 2007

Blanchard River

Flood Stage

Key River and

Stream Reaches

Floodplain

• Need zoomed in figure in town

City of Findlay

Blue:

Existing “100-Year”

Orange :

USACE Recommended

Project “100-Year”

100-yr Hypothetical and

2007 Calibrated HydrographWe’re active members of the communities we serve. That’s why at Stantec, we always design with community in mind.

Insert

Hydrographs

Viable Array of Plans – Findlay

Viable Array of Plans - Ottawa

Concept

Designs

Reviewed

Blanchard River

watershed

– 346 sq. miles

Eagle Creek

Diversion

watershed

– 51 sq. miles

15%

Scope

• Gap Analysis

• Proof of Concept

• Field surveys and geotechnical explorations

• Preferred channel alignment

• Final design and construction plans

• Regulatory permitting

Current Work

Project Review

Gap Analysis

Data Reviewed

• Reports

• Files on USACE

External Hard Drive

• Public Data (USGS,

ODOT, etc.)

Project Components

• H&H

• Base Map Data

• Geotechnical

• Transportation

• Cost

• Economics

• Design

• Environmental

Hydrology – Statistical Study

“There would be a minimal performance of Alternative 13 when storm events are primarily over either the Blanchard River or Lye Creek watersheds upstream of Findlay, with minimal storm events over the Eagle Creek watershed.” USACE Feasibility Study

Will Eagle Creek diversion work?

• Probability of a discharge of X on Eagle Creek when the

Blanchard River in Findlay experiences a discharge of Y

• Appropriately size Eagle Creek diversion for desired flood risk

reduction

Hydrology – Statistical Study

Site Specific DataTemporal Pattern:

• Analysis of actual historic storm data

• SCS Type II -vs- Huff -vs- NOAA Atlas 14 -vs- local data

Storm Sizes:

• Defining “Small”, “Medium”, “Large” storms

Spatial Distribution:

• Actual storm data

Probability:

• Supports Monte Carlo Analyses

Hydrology – Statistical Study

Multi-variate analyses:Return Periods:

• 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year hypothetical storm events

Durations:

• 1-, 3-, 6-, 12-, 24-, 48-hour events

Temporal + Storm Size + Spatial Distribution:

• AWA + NOAA Atlas 14 temporal distribution

Storm Centering

• Multiple centers (at least 4)

Monte Carlo Simulation

• Risk Profile Development

Options ConsideredProject

Refinements

25-Year 50-Year 100-Year

01 Lands & Damages 6,580,000$ 6,777,400$ 7,238,000$

02 Relocations 14,590,000$ 15,027,700$ 15,465,400$

04 Water Control Structure 1,758,000$ 1,758,000$ 1,758,000$

06 Fish & Wildlife 2,657,000$ 2,710,140$ 2,816,420$

08 Roads, Railroads Bridges 34,587,000$ 34,587,000$ 34,587,000$

09 Channels and Canals 8,708,000$ 8,969,240$ 10,188,360$

18 Cultural Resources 692,000$ 709,300$ 795,800$

30 Eng & Design 8,182,000$ 8,304,730$ 9,082,020$

31 Construction Management 3,149,000$ 3,196,235$ 3,495,390$

First Costs 80,903,000$ 82,039,745$ 85,426,390$

Interest during construction 5,671,000$ 5,727,710$ 5,784,420$

Total Cost 86,574,000$ 87,767,455$ 91,210,810$

Channel Sizing Estimates

Channel Size Costs EstimateEagle Creek

25-year 3,000 cfs

50-year 3,500 cfs

100-year 4,050 cfs

500-year 5,400 cfs

Flow Table – Blanchard River

Event Flow (cfs) WSE WSE Δ from 100-Year Depth

500-Year 18,178 778.52 1.67 21.02

250-Year 15,770 777.80 0.95 20.3

100-Year 13,355 776.85 0 19.35

minus 1,000 cfs 12,355 776.23 -0.62 18.73

50-Year 11,550 775.78 -1.07 18.28

minus 2,000 cfs 11,355 775.67 -1.18 18.17

minus 3,000 cfs 10,355 775.03 -1.82 17.53

25-Year 9,848 774.64 -2.21 17.14

minus 4,000 cfs 9,355 774.16 -2.69 16.66

minus 5,000 cfs 8,355 773.53 -3.32 16.03

10-Year 7,495 772.71 -4.14 15.21

minus 6,000 cfs 7,355 772.65 -4.2 15.15

minus 7,000 cfs 6,355 771.62 -5.23 14.12

5-Year 5,653 770.79 -6.06 13.29

At Main Street Bridge - XS 295930

Riffle / Dam

Structures

Channel Modification

Norfolk & Southern BridgeConstrictions

• Questions

• Discussion

Closing