Heath Delzell – Engineering Bureau

IDNR Engineering

Progress to Date and Timeline for Project CompletionDesign and Construction Obstacles

Construction ActivitiesPhase 1 – Dam and

Spillway RenovationPhase 2 - In-Lake

ConstructionSediment Retention

Basins Sediment RemovalShoreline ArmoringUniversally Accessible

Fishing PierPhase 3 – Boat Ramp

and Parking Lot

Progress – Phase 1 History

1991 – Voids filled under spillway

2007 – Contracted French-Reneker Associates to determine cause

2008 – F-R concluded leak in weathered bedrock

Solution: Remove weathered bedrock

StatusF-R Design complete and

permitted for constructionFunding has been

securedCurrently out for bids –

Letting date October 21, 2010

Timeline – Phase 1Winter 2010

Early Start Date: December 1, 2010

Portion of dam to be removed

Tree ClearingConcrete Removal

Timeline – Phase 1Spring-Summer 2011

Excavate Core Trench

Construct Principal Spillway Outlet/Drawdown Pipe

Place Embankment Fill

Timeline – Phase 1Summer-Fall 2011

Place Embankment FillConstruct Principal

Spillway InletAuxiliary Spillway

GradingClose Drawdown Pipe

Winter 2011 – No Construction

Spring 2012Final GradingProject Complete: May

31, 2012

Progress – Phase 2Sediment Retention

BasinsUpper Arm Basin

Preliminary DesignDesigned as a

Sediment PondFilled with Dredge

Material1-2 feet deep

State Contract for completionFinish DesignApply For PermitWetland Mitigation Plan

Progress – Phase 2Sediment Retention

BasinsCampground Arm

Design Complete Increasing Dam

HeightSame function as

Upper Arm Basin

Progress – Phase 2Sediment Removal

Design CompleteRemoving sediment via

mechanical meansScrapers, Bulldozers,

Excavators, Etc.Shoreline Armoring

Design CompletePlacing Riprap in

normally inaccessible locations

Universally Accessible Fishing PierDesign 95% Complete

Timeline – Phase 2Winter 2010

Design and permit application complete January 1Wetland mitigation

Spring 2011Bid Letting: March 17,

2011Early Start Date: May 1,

2011Summer-Fall-Winter 2011

ConstructionSpring 2012

Final Grading and SeedingProject Completion: March

15, 2012

Progress – Phase 3Boat Ramp and

Parking LotDesign is 25%

completeSchedule dependant

on Phase 21-2 Months for

construction

Construction ObstaclesRAIN!!!

Dam construction would slowLarge storms can severely erode a partially

constructed damSediment removal would stop

Green Valley <10% complete

Construction ObstaclesPerspective:

Annual Precipitation for Brighton (inches)

1991 / 2008 1992 / 2009 1993 / 2010

44.0”

30.2”

55.3”

40.5”

54.3”

48.4”

ConclusionDam construction

begins in DecemberPhase 2 starts

Spring 2011Boat Ramp starts

Fall 2011 or Spring 2012

All phases should be complete and the lake nearly full by the end of May 2012