floodplain management and restoration in charlotte-mecklenburg dave canaan director – water &...
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Floodplain ManagementFloodplain Management and Restoration in and Restoration in Charlotte-MecklenburgCharlotte-Mecklenburg
Dave CanaanDirector – Water & Land Resources
Storm Water ManagementStorm Water Management
CHARLOTTE-MECKLENBURGSTORM WATER SERVICES
Mecklenburg County SWS FEMA streams (> 1 sq. mi. watershed) County areas (pipes, swales, ditches) 5 of 6 towns (pipes, swales, ditches)
City of Charlotte SWS Open systems (creeks & swales) Closed systems (culverts & pipes)
BackgroundBackground
County Storm Water Major Streams
– FEMA or mapped streams/river– Greater than 1 square mile
drainage area– County wide
Minor System – Less than 1 square mile
drainage area
BackgroundBackground
County Storm Water Partnerships ($1.8M)
– City– NPDES Permit– BMP projects
– Towns– NPDES Permit– Investigations, design and
construction
BackgroundBackground
Municipalities ($35M+/-) Minor System
– Less than 1 square mile drainage area
– Programs vary greatly Water Quality per CWA
County VisionCounty Vision
A safe community A healthy community A livable community A prosperous community A well-governed community
Priorities in Mecklenburg County:
Commitment at the TopCommitment at the Top
““The Little Sugar Creek watershed is The Little Sugar Creek watershed is one of the most severely polluted one of the most severely polluted watersheds in North Carolina (NCDWQ watersheds in North Carolina (NCDWQ Catawba River Basinwide Water Quality Catawba River Basinwide Water Quality Plan pp. 4-24 to 4-27).”Plan pp. 4-24 to 4-27).”
"The County Commission herein finds that the "The County Commission herein finds that the public policy of Mecklenburg County is that our public policy of Mecklenburg County is that our surface waters --- creeks, tributaries, ponds and surface waters --- creeks, tributaries, ponds and lakes --- are lakes --- are a natural resource to be protecteda natural resource to be protected as a as a source of natural beauty and recreation.source of natural beauty and recreation.
Further, that the use of our creeks, tributaries, Further, that the use of our creeks, tributaries, ponds and lakes as a ponds and lakes as a stormwater disposal method stormwater disposal method shall be secondaryshall be secondary to the preservation of creeks, to the preservation of creeks, tributaries, ponds and lakes.”tributaries, ponds and lakes.”
Multi-objective Floodplain Multi-objective Floodplain PlanningPlanning
BOCC Adopted Initiatives; Floodplain Management Guidance Doc. (Dec 97) SWIM Initiative (Dec 99) Greenway Master Plan (1999) Flood Mitigation Plans (2003) All Hazards Plan (2005)
Charlotte-MecklenburgCharlotte-Mecklenburg
Sugar CreekSugar Creek
Little Sugar CreekLittle Sugar Creek
HiddenHiddenValleyValley
Watersheds / BasinsWatersheds / Basins
330± miles of FEMA streams
32 watersheds
All water in Mecklenburg County (except Catawba River) originates in Mecklenburg County
MissionMission
Reducing the potential for the loss of life and property due to flooding.
Enhancing the natural and beneficial functions of the floodplain.
Floodplain Management strives to build a Floodplain Management strives to build a Livable Community byLivable Community by::
Floodplain Management Floodplain Management Goals & ObjectivesGoals & Objectives
Mitigation/RestorationMitigation/Restoration(Correction)(Correction)
PRESERVATION (Protection)
PASTPASTFUTUREFUTURE
PROJECTSPROJECTS
ORDINANCESORDINANCES
County Storm Water ServicesCounty Storm Water ServicesCapital ProgramCapital Program
Three Components: Flood Mitigation Program Water Quality Program Engineering Program
(Stream Restoration/Repairs)
PARTNERSHIPS
Floodplain Management Floodplain Management PartnersPartners
Floodplain Management Floodplain Management ElementsElements
Creek Maintenance Rainfall / Stream Gauges Flood Information and Notification
System Floodplain Remapping Customer Service Requests Stream Restoration Flood Mitigation Planning Floodplain Buyout Program
MaintenanceMaintenance
Storm Water Operations Division Blockage Removal Encroachments / Notices of Violation Vegetation Management Acquired parcel maintenance
Floodplain Management Floodplain Management ElementsElements
Creek Maintenance Rainfall / Stream Gauges Flood Information and Notification
System Floodplain Remapping Customer Service Requests Stream Restoration Flood Mitigation Planning Floodplain Buyout Program
Rainfall / Stream GaugesRainfall / Stream Gauges
PARTNERPARTNER
United States United States Geologic Geologic SurveySurvey
(USGS)(USGS)
Floodplain Management Floodplain Management ElementsElements
Creek Maintenance Rainfall / Stream Gauges Flood Information and Notification
System Floodplain Remapping Customer Service Requests Stream Restoration Flood Mitigation Planning Floodplain Buyout Program
Early Warning SystemEarly Warning System
Warning dissem ination
subsystem
Data collection & transm ission
subsystem
Data filing, displaying, & dissem inating
subsystem
Forecasting subsystem
Threat- recognition subsystem
Flood response plan
Response and recovery
( c) 1999, Dav id F o rd C onsu lting Engineers
W arning
Early Warning SystemEarly Warning System
Floodplain Management Floodplain Management ElementsElements
Creek Maintenance Rainfall / Stream Gauges Flood Information and Notification
System Floodplain Remapping Customer Service Requests Stream Restoration Flood Mitigation Planning Floodplain Buyout Program
Re-Mapping - 1999Re-Mapping - 1999
1975: Flood Insurance Rate 1975: Flood Insurance Rate Maps (FIRM)Maps (FIRM)
Community Rating System Community Rating System (insurance discounts)(insurance discounts)
1999-2001:1999-2001:
Re-Mapping - 1999Re-Mapping - 1999
Re-MappingRe-Mapping
STUDY STUDY RESULTSRESULTS
Existing Existing ConditionsConditions
+2.0 feet +2.0 feet
Future Future ConditionsConditions
+4.6 feet+4.6 feet
3,000 - 4,000
3,000 - 4,000
structures in
structures in
the floodplain
the floodplain
Floodplain Management Floodplain Management ElementsElements
Creek Maintenance Rainfall / Stream Gauges Flood Information and Notification
System Floodplain Remapping Customer Service Requests Stream Restoration Flood Mitigation Planning Floodplain Buyout Program
Service RequestsService Requests
Irwin Creek at I-77
FloodingFlooding
ErosionErosion
BlockagesBlockages
Property DamageProperty Damage
Floodplain Management Floodplain Management ElementsElements
Creek Maintenance Rainfall / Stream Gauges Flood Information and Notification
System Floodplain Remapping Customer Service Requests Stream Restoration Flood Mitigation Planning Floodplain Buyout Program
History OverviewHistory Overview
1890’s - 1920’s: Catawba River dams Duke Energy
1910’s - 1930’s: creek dredging, widening drainage, irrigation, agricultural districts
1950’s: chemical deodorizers Meck County Dept. of Environmental Protection
1960’s - 1995: riprap engineering department
1995 - present: soil bioengineering Storm Water Services
1890’s - 1920’s1890’s - 1920’s
Catawba River dams - Duke Energy Series of 11 dams/reservoirs drinking water, hydro power, flood control, navigation created setbacks & buffers from water bodies swimming, fishing & recreation
1910’s - 1930’s1910’s - 1930’s
US Army Corps of Engineers Creating navigable waters of the state & U.S.
“Dredge on Briar Creek”
Dredge, Widen, StraightenDredge, Widen, Straighten
Agricultural Districts better field drainage eliminated “swamps” &
“marshes” no more groundwater recharge
“Drainage Work in Mecklenburg
County”
circa 1911
Dredge, Widen, StraightenDredge, Widen, Straighten
Old creek alignment for Little Sugar Creek
New & “improved” alignment for Little Sugar Creek
Sewer Department centralized collection & treatment, first WWTP, 1923
Dredge, Widen, StraightenDredge, Widen, Straighten
Federal Funding North Carolina Emergency
Relief Administration, 1936
“Clearing Little Sugar Creek & tributaries”
“Cleaning out Long Creek”“Clear & ditch Toby
Creek”“Briar Creek drainage”
“Drainage of McDowell Creek”
$16,076.70
$3,877.30$95,406.47
$2,627.70
$3,447.10
1950’s1950’s
“Chemical deodorizers should take of it!” Meck County Dept. of
Environmental Protection
County streams had little aquatic life, minimal vegetative cover and strong odors.
1960’s - 19951960’s - 1995
Riprap - King of the Queen City! Worked for just about any engineering “solution” Fixes the stream horizontally Environmental consequences of “flush & gush” weren’t
understood Environmental movement was in its infancy 1972 - Clean Water Act
Bio EngineeringBio EngineeringIrwin Creek (1998)
Natural Channel DesignNatural Channel Design
Hydraulic response ….. altered dimension
A narrower thalweg forms in Briar Creek TWO months after placing SIX alternating rock vanes (2000).Briar Creek, August 12,
2000
Floodplain Management Floodplain Management ElementsElements
Creek Maintenance Rainfall / Stream Gauges Flood Information and Notification
System Floodplain Remapping Customer Service Requests Stream Restoration Flood Mitigation Planning Floodplain Buyout Program
Flood Mitigation PurposeFlood Mitigation Purpose
Community Health and Safety Focus Area
Reduce Injury
Flood Mitigation Flood Mitigation Planning HistoryPlanning History
1997 Floodplain Management Guidance Document
1999 Adopted original Watershed Plans
2000 Initiate Mitigation (Buyout) Program
2004 Adopted updated Watershed Plans
2004 Expanded Flood Mitigation Capital Program
Floodplain Management Floodplain Management ElementsElements
Creek Maintenance Rainfall / Stream Gauges Flood Information and Notification
System Floodplain Remapping Customer Service Requests Stream Restoration Flood Mitigation Planning Floodplain Buyout Program
Problem DefinitionProblem Definition
Doral ApartmentsBriar Creek July 22-24, 1997
3,000 - 4,000
3,000 - 4,000
structures in
structures in
the floodplain
the floodplain
Problem DefinitionProblem Definition
Myers Park ManorBriar Creek July 22-24, 1997
Flood MitigationFlood MitigationAccomplishmentsAccomplishments
Years 2000 - 2005 135 buildings removed from the
floodplain (90% participate) 80 acres of deeded public open
space Buyout Funding (Awarded)
$14.1M - Federal Funds $1.7M - State Funds $8.9M - Local Storm Water Funds
35 additional buildings & 40 acres of open space within the floodplain through efforts with Real Estate Services
Buyout ProgramBuyout Program
Issues Voluntary = No Condemnation Fair Market Value Prioritizing thru Mitigation Plans Demolition vs. Relocation Owners vs. Renters Hazardous Materials Vacant Land & What to Do With It
Buyout AreaBuyout Area
Wes
tfie
ld R
oad
Wes
tfie
ld R
oad
Brandywine RoadBrandywine Road
Future ParkFuture ParkRoad ShoppingRoad ShoppingCenter (1956)Center (1956)
Future MyersFuture MyersPark ManorPark Manor
(1951)(1951)
Lit
tle S
ug
ar
Cre
ek
Lit
tle S
ug
ar
Cre
ek
19381938
19511951
19561956Lit
tle S
ug
ar
Cre
ek
Lit
tle S
ug
ar
Cre
ek
Future Woodlawn Road
Future Woodlawn Road
MyersMyersParkPark
ManorManorFuture ParkFuture Park
Road ShoppingRoad ShoppingCenter (1956)Center (1956)
MyersMyersParkPark
ManorManor
Lit
tle S
ug
ar
Cre
ek
Lit
tle S
ug
ar
Cre
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ParkParkRoadRoad
ShoppingShoppingCenterCenter
Buyout AreaBuyout Area
19971997
19951995
20032003
BEFORE
Buyout AreaBuyout Area
AFTER
High WaterBEFORE - July 97
AFTER
Buyout AreaBuyout Area
Hidden Valley - Step 1Property Acquisition
(1) Fee Title
(2) Deed Restriction
(3) Voluntary
(4) No Condemnation
Buyout AreaBuyout Area
Hidden Valley - Step 2Structure Demolition
(1) Relocation
(2) Habitat for Humanity
(3) Fire Dept. Training
(4) SWAT Police Training
Buyout AreaBuyout Area
Hidden Valley - Step 3Environmental Restoration
(1) Environmental
(2) Water-Oriented
(3) Open Space / Re-Forested
(4) Greenway / Recreational
Buyout AreaBuyout Area
Hidden Valley Eco-Restoration Wetland $1± million acquisition cost $1.2± million construction cost $940,000 CWMTF grant 1½ sq. mile watershed 17 homes purchased & razed greenway planned additional vacant land purchases additional funds from Wetlands Restoration Program
THANK YOU