Eating the Elephant: Stormwater Management for Boone County Georganne Bowman, Stormwater Coordinator – Boone County, MO ----- Christina Luebbert, P.E.,

Eating the Elephant: Eating the Elephant: Stormwater Management Stormwater Management

for Boone Countyfor Boone County

Georganne Bowman, Stormwater Coordinator – Georganne Bowman, Stormwater Coordinator – Boone County, MOBoone County, MO

----------Christina Luebbert, P.E., CFM, Project Manager – Shafer, Christina Luebbert, P.E., CFM, Project Manager – Shafer,

Kline and Warren, Inc.Kline and Warren, Inc.

One Bite at a Time…One Bite at a Time…

1.1. Build a comprehensive Build a comprehensive stormwater program for the stormwater program for the CountyCounty

2.2. Fix the internal processesFix the internal processes3.3. Develop regulations that Develop regulations that

encourage stormwater encourage stormwater management flexibility and management flexibility and growthgrowth

Community DirectionCommunity Direction

ObstaclesObstacles– Political ClimatePolitical Climate

Buffer RegulationsBuffer Regulations City of Columbia ordinance/manualCity of Columbia ordinance/manual Hinkson Creek TMDLHinkson Creek TMDL

– Internal ChangesInternal Changes Legal staff, management, new staffLegal staff, management, new staff Minimal standards/codes buried in Road & Minimal standards/codes buried in Road &

Zoning RegulationsZoning Regulations

Community DirectionCommunity Direction

The good news…The good news…– Hinkson Creek projectHinkson Creek project

TMDL developmentTMDL development

– Additional monitoring – UMCAdditional monitoring – UMC– Partnering efforts with the City and UMC Partnering efforts with the City and UMC – Stormwater Task Force suggestionsStormwater Task Force suggestions

Protection for homeowners from floodingProtection for homeowners from flooding Stream Buffer protectionStream Buffer protection

Comprehensive ProgramComprehensive Program

Common sense approach to Common sense approach to compliancecompliance– Fix what needs to be fixedFix what needs to be fixed– Do not implement programs just to Do not implement programs just to

satisfy the permitsatisfy the permit


Develop a long-range plan & set Develop a long-range plan & set prioritiespriorities

Develop a comprehensive program Develop a comprehensive program for each MCMfor each MCM


5-year plans5-year plans– IDDEIDDE

Select the small handful of politically “HOT” Select the small handful of politically “HOT” chemicals. chemicals.

Collect some data.Collect some data. Tell a story about the hot topics.Tell a story about the hot topics. Bring attention to the IDDE program.Bring attention to the IDDE program. Get more $ next year to do more good Get more $ next year to do more good

stuff, and broaden scope.stuff, and broaden scope.


MCM 3 – Illicit Discharge Detection and Elimination

Goal: Develop a program to reduce illegal connections and discharges to the County system

Develop an ordinance Conduct a Storm Sewer Assessment (priority) Develop/conduct monitoring Enforcement Program review and modification


5-year plans5-year plans– ConstructionConstruction

Early plan review and issues meetingsEarly plan review and issues meetings Develop guidance Develop guidance Train inspectorsTrain inspectors Track recommendations and changesTrack recommendations and changes Incremental enforcement Incremental enforcement


MCM 4 – Construction Site Stormwater Runoff Control

Goal: Develop a meaningful program that meets the intent and requirements of the permit by reducing erosion and sediment from construction sites. Development ordinance, and guidance manual Provide construction site oversight, and plan review Develop a training program Enforcement Program review and modification


1.1. Build a comprehensive stormwater Build a comprehensive stormwater program for the Countyprogram for the County

2.2. Fix the internal processesFix the internal processes3.3. Develop regulations that encourage Develop regulations that encourage

stormwater management flexibility stormwater management flexibility and growthand growth

Broken ProcessesBroken Processes

Plan Review Process ImprovementsPlan Review Process Improvements

Problems identifiedProblems identified Cohesion with PZ and PWCohesion with PZ and PW Consistent message to design communityConsistent message to design community Standardize Standardize

– Getting everyone on the same pageGetting everyone on the same page

Concept ReviewConcept Review

More information up frontMore information up front Work with developers/engineers earlier Work with developers/engineers earlier

in processin process Identify environmental issues prior to Identify environmental issues prior to

design dollars being spentdesign dollars being spent– Buffer regulationsBuffer regulations– Karst/sinkhole areasKarst/sinkhole areas


1.1. Build a comprehensive stormwater Build a comprehensive stormwater program for the Countyprogram for the County

2.2. Fix the internal processesFix the internal processes3.3. Develop regulations that encourage Develop regulations that encourage

stormwater management flexibility stormwater management flexibility and growthand growth

OrdinancesOrdinances

Legal AuthorityLegal Authority Started with a basic frameworkStarted with a basic framework

– IDDE, Construction, some Post-ConstructionIDDE, Construction, some Post-Construction

Worked with the new County attorney Worked with the new County attorney – Reviewed the County authority Reviewed the County authority – Class 1 counties are different from citiesClass 1 counties are different from cities

OrdinancesOrdinances

Borrowed ResourcesBorrowed Resources CWP post-construction model ordinanceCWP post-construction model ordinance Karst protection from SpringfieldKarst protection from Springfield Other programsOther programs

– Tree preservation – King CountyTree preservation – King County– Background – Iowa, Wisconsin, Georgia, etcBackground – Iowa, Wisconsin, Georgia, etc

Design GuidanceDesign Guidance

Opposing objectives – Opposing objectives – – Consistent with City of Columbia’s manual Consistent with City of Columbia’s manual – But customized for County style development But customized for County style development

– Feedback from Development community Feedback from Development community issues with City manualissues with City manual

– Value rating systemValue rating system– RedevelopmentRedevelopment


Stakeholder processStakeholder process Engineering communityEngineering community Previous Stormwater Task Force Previous Stormwater Task Force

membersmembers DevelopersDevelopers Staff at Planning and Zoning and Staff at Planning and Zoning and

Public WorksPublic Works


Stakeholder process…Stakeholder process…Positives: Positives:

Early involvement from engineering firmsEarly involvement from engineering firms Open discussion to work out bugs Open discussion to work out bugs Expose commission to languageExpose commission to language

Negatives:Negatives: Tangents/agendas from stakeholdersTangents/agendas from stakeholders Minimal direction/guidance from commissionMinimal direction/guidance from commission


External Review…External Review… Two local engineering firms have agreed Two local engineering firms have agreed

to review the ordinance and design to review the ordinance and design guidance for cost differences. guidance for cost differences.

Objectives:Objectives:The current Boone County design standards, The current Boone County design standards,

The proposed Boone County Stormwater Manual, andThe proposed Boone County Stormwater Manual, and

The current City of Columbia Stormwater manual.The current City of Columbia Stormwater manual.

Stormwater ManagementStormwater Management

Nested Stormwater ApproachNested Stormwater Approach– Runoff ReductionRunoff Reduction– Water Quality Volume TreatmentWater Quality Volume Treatment– Channel ProtectionChannel Protection– Flood Control Safety NetFlood Control Safety Net

Stormwater ManagementStormwater Management

Runoff ReductionRunoff Reduction

To replicate pre-development hydrologic To replicate pre-development hydrologic conditions, and to promote baseflow, conditions, and to promote baseflow, 10% of the water quality volume shall be 10% of the water quality volume shall be permanently reduced.permanently reduced.– by disconnecting impervious areas, by disconnecting impervious areas,

– maintaining sheet flow maintaining sheet flow

– infiltration practices where soils conditions allow and/or infiltration practices where soils conditions allow and/or

– collection and reuse of runoff. collection and reuse of runoff.

Water Quality VolumeWater Quality Volume

To protect the receiving waters from To protect the receiving waters from NPS, the remainder of the water NPS, the remainder of the water quality volume that was not quality volume that was not removed through runoff reduction, removed through runoff reduction, shall be treated through filtration shall be treated through filtration BMPs.BMPs.

Channel ProtectionChannel Protection

The stormwater system shall be The stormwater system shall be designed so that post-development designed so that post-development discharges will not erode natural discharges will not erode natural channels or steep slopes. channels or steep slopes.

Tier 1Tier 1 less than 5 acres of land disturbance OR less less than 5 acres of land disturbance OR less than 20% imperviousness than 20% imperviousness

Tier 2Tier 2 Sites greater than 5 acres of land disturbance OR Sites greater than 5 acres of land disturbance OR greater than 20% imperviousness greater than 20% imperviousness


Tier 1Tier 1 maintain sheet flow maintain sheet flow Use energy dissipaters and level spreaders Use energy dissipaters and level spreaders Conveyances designed to reduce velocity Conveyances designed to reduce velocity Concentrated flows discharged at an elevation that will Concentrated flows discharged at an elevation that will

not cause erosion or require discharge across any not cause erosion or require discharge across any constructed slope or natural steep slopes. constructed slope or natural steep slopes.

Outfall velocities must be non-erosive from the point of Outfall velocities must be non-erosive from the point of discharge to the receiving channel or waterbody where discharge to the receiving channel or waterbody where the discharge point is calculated the discharge point is calculated


Tier 2Tier 2 Site design techniques that decrease runoff Site design techniques that decrease runoff

volumes and peak flows. This shall be volumes and peak flows. This shall be accomplished by controlling the post-accomplished by controlling the post-development peak discharge rate to the pre-development peak discharge rate to the pre-development rate. This criterion shall be met development rate. This criterion shall be met for the 5-year, 24-hour storm event, (or for the 5-year, 24-hour storm event, (or equivalent storm runoff volume using other equivalent storm runoff volume using other methodologies). methodologies).

Flood ControlFlood Control

This criterion shall be met for the 10-This criterion shall be met for the 10-year, 24-hour storm event on year, 24-hour storm event on residentially zonedresidentially zoned properties and the properties and the 25-year, 24 hour storm event on 25-year, 24 hour storm event on non-non-residentially zoned properties. residentially zoned properties.

Stormwater BMPs shall safely pass the Stormwater BMPs shall safely pass the 100-year storm without creating 100-year storm without creating damaging conditions downstream.damaging conditions downstream.

RedevelopmentRedevelopment

Land development that qualifies as Land development that qualifies as redevelopment shall meet one of the redevelopment shall meet one of the following criteria:following criteria:

Reduce Impervious Cover (20%)Reduce Impervious Cover (20%) Provide Treatment (20% & 100%)Provide Treatment (20% & 100%) Apply Innovative ApproachesApply Innovative Approaches Provide Off-Site Treatment Provide Off-Site Treatment Address Downstream Issues Address Downstream Issues Combination of MeasuresCombination of Measures

ConclusionConclusion

Boone County is currently developing a Boone County is currently developing a comprehensive ordinance and guidancecomprehensive ordinance and guidance

Consider the political and community Consider the political and community valuesvalues

Trying untested approaches, andTrying untested approaches, and Encourage flexibilityEncourage flexibility

For more information:For more information:http://www.showmeboone.com/http://www.showmeboone.com/and follow the links to Stormwaterand follow the links to Stormwater

Georganne Bowman, Boone County Public WorksGeorganne Bowman, Boone County Public [email protected]@boonecountymo.org

573-449-8515573-449-8515----------

Christina Luebbert, P.E., CFM – SKWChristina Luebbert, P.E., CFM – [email protected]@skw-inc.com

573-442-4537573-442-4537

http://www.showmeboone.com/

Eating the Elephant: Stormwater Management for Boone County Georganne Bowman, Stormwater Coordinator – Boone County, MO ----- Christina Luebbert, P.E.,

Documents

comprehensive program

idde program

growth slide

mcm slide

meaningful program

modification slide

permit slide

page slide