Atl Bch SWMP Presentation 02-27-2012 (02-24)
City of Atlantic BeachCity of Atlantic Beach
Stormwater Master Plan UpdateStormwater Master Plan Update
February 27 2012
Meeting Purpose: Update City Commission on Meeting Purpose: Update City Commission on
the Stormwater Master Plan Updatethe Stormwater Master Plan Update
Overview of StormWater Master Plan (SWMP) Update and City
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Implementation
Present Capital Improvement Projects
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Review and Update of Onsite Retention Requirement
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Ditch Rehabilitation Options
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The City has updated the SWMP to Account for The City has updated the SWMP to Account for
Recent Development and InformationRecent Development and Information
1995 Citywide Master Plan1995 Citywide Master Plan
2001 Core City Project2001 Core City Project
2002 Master Plan Update2002 Master Plan Update
Hopkins CreekHopkins Creek
2010 Duval/FEMA Map updates2010 Duval/FEMA Map updates
2011 Citywide update2011 Citywide update
The City Implemented 22 CostThe City Implemented 22 Cost--effective effective
Projects to Reduce Flooding Since 1999Projects to Reduce Flooding Since 1999
ProjectCost
1. 1999 Stormwater Improvements$415,000
2. W. 13th Street Drainage Improvements$39,000
3. Sherry Drive Reconstruction$1,375,000
4. Selva Marina Improvements$317,000
5. Core City$4,784,000
6. Dewees/Coquina Drainage & Paving Imps.$134,000
7. Church Rd. Water & Road Imps.$152,000
8. Plaza Road Turn Lane for Post Office$55,000
9. Jordan Street Paving & Drainage$109,000
Selva Marina -2001
10. Town Center Phase III$130,000
11. Country Club Lane$84,000
12. George & Dudley Drainage Improvements$98,000
13. Seminole Ditch Headwall$13,000
14. Ocean Blvd. -13th Street Drainage$139,000
15. Selva Grande Ditch Headwall$26,000
16. Ocean Blvd. -14th-16th Drainage$272,000
17. George St. Sidewalk & Drainage$36,000
18. Ardella Road Drainage Project$4,000
19. Royal Palms Stormwater Project$3,125,000
20. Cavalla Road Bulkheads$9,000
21. Selva Tierra Ditch Improvements$26,000
Cavalla Road 2007
22. Hopkins Creek Regional Pond$1,573,000
HOPKINS CREEK RSF
Total$12,915,000
-2008
Aquatic Drive -2003
These Projects Also Saved the City Over $8 Million in
Capital Costs and Preserved Historic Parks, Trees, and
Wetlands
Improved Flood Control LOS
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T. S. Fay
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Increased Treatment and Water
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Quality Benefits
New Park
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Seminole Road Ditch Seminole Road Ditch
20072007
Core City Project Core City Project --20012001
Hopkins Creek Facility Hopkins Creek Facility
and Park and Park --20082008
This Update AddressesThis Update Addresses
Additional guidance and options for onsite stormwater Additional guidance and options for onsite stormwater
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volume controls (LID)volume controls (LID)
Remaining nuisance ponding and system connectivityRemaining nuisance ponding and system connectivity
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Ditch safety and increased maintenance Ditch safety and increased maintenance
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FDEP NPDES MS4 permit support and emerging regulationsFDEP NPDES MS4 permit support and emerging regulations
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GIS CoordinationGIS Coordination
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Potential sea level rise impacts on the systemPotential sea level rise impacts on the system
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Stormwater Stormwater Management Management GoalsGoals
Then and NowThen and Now
Flood ControlFlood Control
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Water Water Quality ProtectionQuality Protection
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Wetlands Wetlands ManagementManagement
LevelsLevels
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ofof
Aquifer Aquifer Recharge Recharge
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ServiceService
ConservationConservation
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Operation Operation and Maintenanceand Maintenance
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Community Community AcceptanceAcceptance
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SustainabilitySustainability
Capital Improvement Plan (CIP)Capital Improvement Plan (CIP)
CDM gathered information from several CDM gathered information from several
sources to identify the next list of CIP Projectssources to identify the next list of CIP Projects
Site visitsSite visits
Data reviewData review
Selection of 2 projects for detailed Selection of 2 projects for detailed
engineering evaluationengineering evaluation
Conceptual improvementsConceptual improvements
Cost estimates for 10 projectsCost estimates for 10 projects
The Projects Were Scored by CDM and City The Projects Were Scored by CDM and City
Staff for the Following CategoriesStaff for the Following Categories
Public Safety
•Based on potential risk from stormwater flooding and ponding
Daily Traffic Impacted
•Based on road classification and other access, with higher scores for
arterial/collector roads
Nuisance to Residents
•Based on observed field conditions, topographic evaluation, and
input from City staff
History of Complaints Received
•Based on complaints submitted by citizens to City staff
Capital Improvement Plan EvaluationsCapital Improvement Plan Evaluations
Capital Improvement Project Capital Improvement Project
RankingRanking
35 locations evaluated35 locations evaluated
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11 Ditches evaluated11 Ditches evaluated
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10 cost estimates for higher 10 cost estimates for higher
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priority projectspriority projects
2 projects evaluated in detail2 projects evaluated in detail
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Project RankingProject Ranking
A total of 42 problem areas were visited and evaluated as part of the evaluation. A total of 42 problem areas were visited and evaluated as part of the evaluation.
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Recommended CIPRecommended CIP
Conceptual Capital
RankProject
Cost Estimate
1East Coast Drive -Atlantic to Ahern$ 360,000
2Seminole Road Ditch$ 3,400,000
Salt Air Drainage Upgrades -Magnolia (100 block)/Poinsettia Streets (100 & 200 Block)/Pine
3St$ 250,000
4Oceanwalk ditch (between OW and Selva Norte)$ 0
5100 / 200 / 300 Block Seminole$ 580,000
61080 West Plaza at Carnation and Gladiola at West Plaza$ 120,000
7Begonia street –West 6th to 9th$ 350,000
8Main Street between Levy and Stewart$ 530,000
9Mealy Street industrial area and Dudley Street west of Donner Park$ 25,000
10Robert St/ Lewis St/ Dudley St Ditch$ 171,000
TOTAL$ 5,846,000
Onsite Stormwater Controls and OptionsOnsite Stormwater Controls and Options
Flooding Will Increase Without Stormwater Controls Flooding Will Increase Without Stormwater Controls
and Onsite Controls are Most Costand Onsite Controls are Most Cost--effective effective
City StreetsCity Streets
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Adjacent Adjacent
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propertiesproperties
Downstream Downstream
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systemssystems
Water quality Water quality
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ImpactsImpacts
Reduced rechargeReduced recharge
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Current Ordinance OverviewCurrent Ordinance Overview
Application of Low Impact Development concepts to Application of Low Impact Development concepts to
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redevelopment by more than 10% or 400 sqredevelopment by more than 10% or 400 sq--ft of impervious ft of impervious
areaarea
No net loss of onsite surface storage (to avoid displacing No net loss of onsite surface storage (to avoid displacing
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historic onsite stormwater onto adjacent parcels and to historic onsite stormwater onto adjacent parcels and to
maintain existing aquifer recharge)maintain existing aquifer recharge)
No increase in runoff volume for the 25 year 24 hour design No increase in runoff volume for the 25 year 24 hour design
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storm (to avoid increases in runoff volume, flooding and storm (to avoid increases in runoff volume, flooding and
pollution to offsite while maintaining aquifer recharge) pollution to offsite while maintaining aquifer recharge) ––
SJRWMD StandardSJRWMD Standard
Onsite Stormwater Control EvaluationOnsite Stormwater Control Evaluation
Test areaTest area
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Evaluation for existing and potential redevelopment Evaluation for existing and potential redevelopment
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conditionsconditions
Impervious area, Impervious area,
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Groundwater tableGroundwater table
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Driveway / grassed area
Select FillSelect Fill
Considered four LID BMPsConsidered four LID BMPs
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PerforatedPerforated
PipePipe
ExfiltrationExfiltration
Swales/retentionSwales/retention
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ExfiltrationExfiltration
Rain gardens/bioretentionRain gardens/bioretention
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CourseCourse
AggregateAggregate
(Washed)(Washed)
Filter FabricFilter Fabric
Exfiltration trenchExfiltration trench
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tt
22--3 Fee3 Fee
ExfiltrationExfiltration
Seasonal High Water TableSeasonal High Water Table
Underground storageUnderground storage
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Test Area EvaluatedTest Area Evaluated
81 Parcels 81 Parcels
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Total Area: 17.7 AcresTotal Area: 17.7 Acres
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Existing parcels impervious Existing parcels impervious
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Range: 0Range: 0--78%78%
Composite : 32% imperviousComposite : 32% impervious
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Swales and RetentionSwales and Retention
Can be a traditional swale or a shallow Can be a traditional swale or a shallow
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grassed yard retention area for dual usegrassed yard retention area for dual use
Should be at least 1 ft above seasonal Should be at least 1 ft above seasonal
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high groundwater tablehigh groundwater table
Should be maintainable by homeownerShould be maintainable by homeowner
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Bioretention (Rain Gardens)Bioretention (Rain Gardens)
Special form of a swale or retentionSpecial form of a swale or retention
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Added aesthetic factor with plants/flowersAdded aesthetic factor with plants/flowers
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Must retain the required volume below the overflow Must retain the required volume below the overflow
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elevation elevation
Exfiltration TrenchesExfiltration Trenches
Underground optionUnderground option
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Can go under pavement or grassed areasCan go under pavement or grassed areas
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Filter wrap around perforated pipe and trenchFilter wrap around perforated pipe and trench
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Driveway/Grassed Surface
Select FillSelect Fill
PerforatedPerforated
PipePipe
ExfiltrationExfiltration
ExfiltrationExfiltration
CourseCourse
AggregateAggregate
22--3 Feet3 Feet
))
(Washed(Washed
Filter FabricFilter Fabric
ExfiltrationExfiltration
ee
Seasonal High Water TablSeasonal High Water Tabl
Underground StorageUnderground Storage
An alternative consists in excavating underground An alternative consists in excavating underground
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vaults/pipes that can provide runoff retention volume.vaults/pipes that can provide runoff retention volume.
Access required for maintenance.Access required for maintenance.
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Onsite Stormater Controls are the Most CostOnsite Stormater Controls are the Most Cost--
Effective and Practicable OptionEffective and Practicable Option
Swale/Swale/
RetentionRetention
Conceptual Costs to Meet the Current Conceptual Costs to Meet the Current
OrdinanceOrdinance
Swales or yard retention are the most costSwales or yard retention are the most cost--effective effective
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controls and allow for dual usecontrols and allow for dual use
Based on all parcels applying the same BMP typeBased on all parcels applying the same BMP type
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Offsite
Swale/ Exfiltration Underground
BioretentionUnderground
RetentionTrenchVault
Vault
Test Area
$18,300$144,100$210,700$352,500$673,000
Total Cost
Ratio36.84.73.21.91.0
Cost per
$200$2,900$4,300$7,200$13,700
Parcel
Cost/cu-ft$0.40$2.80$4.10$6.80$13.10
The City is already providing a credit for infiltrationThe City is already providing a credit for infiltration
Soil Boring Information
Credit for storage available between Credit for storage available between
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the BMP and 1+ ft above the seasonal the BMP and 1+ ft above the seasonal
high groundwater elevationhigh groundwater elevation
Further credit refinement would Further credit refinement would
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require additional groundwater and require additional groundwater and
soil datasoil data
Maintain the current credit based on Maintain the current credit based on
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depth to groundwater, given the depth to groundwater, given the
current data available current data available
Ditch Maintenance and Capital ImprovementsDitch Maintenance and Capital Improvements
Ditch Maintenance is a priority for the Ditch Maintenance is a priority for the
Stormwater DivisionStormwater Division
Inventory of City Stormwater Infrastructure
Underground pipes140,000 LF
Swale/Ditch 36,000 LF
Wet Ditch/Channel 38,000 LF
Baffle Box 3 UN
Culvert Crossing 6 UN
Special Equipment:
Wet Detention Ponds6 UN
Menzi Muck Machine
Weirs4 UN
Pump Stations1 UN
Dry Retention Ponds2 UN
Outfalls5 UN
CDM Inspected Several Major DitchesCDM Inspected Several Major Ditches
Flood ControlFlood Control
Water Quality Water Quality
Traffic/Pedestrian SafetyTraffic/Pedestrian Safety
Private PropertyPrivate Property
Tree Protection/City aestheticsTree Protection/City aesthetics
Life Cycle CostLife Cycle Cost
Levy Road
Seminole Road
Robert Street Ditch–FDOT
11 Ditches Evaluated
mfs1
Evaluation of
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Alternatives: 1
Dynamic evaluation: 5
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Rational method: 5
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Slide 29
mfs1 Too much info for Commission?
Michael Schmidt, 2/24/2012
Ditch Rehabilitation and Maintenance Ditch Rehabilitation and Maintenance
EvaluationsEvaluations
Ownership and AccessOwnership and Access
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EasementsEasements
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RightsRights--ofof--way (ROWs)way (ROWs)
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Level of ServiceLevel of Service
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MaintainabilityMaintainability
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EquipmentEquipment
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Ditch rehabilitation considers several factorsDitch rehabilitation considers several factors
Adjacent Structures
•Potential settling and vibration.
Adjacent Roads
•Excavation trench considerations and maintenance of traffic
Environmental Resource Permit
•Cannot increase peak flows or flood levels
Maintenance
•City needs an accessible easement or ROW
Seminole Road Ditch Scored the 2Seminole Road Ditch Scored the 2Highest Highest
ndnd
Score Citywide due to Adjacent Arterial RoadScore Citywide due to Adjacent Arterial Road
Safety Safety concernsconcerns
City has planted trees to reduce City has planted trees to reduce
hazardhazard
Frequent complaintsFrequent complaints
Seminole Road Ditch EvaluationSeminole Road Ditch Evaluation
Project ranked # 2 citywideProject ranked # 2 citywide
Detailed engineering Detailed engineering
evaluationevaluation
Comparison of existing Comparison of existing
condition and 2 alternativescondition and 2 alternatives
Required to maintain Required to maintain
hydraulic conveyance to hydraulic conveyance to
avoid increasing peak flow avoid increasing peak flow
rates downstreamrates downstream
Seminole Road Ditch Seminole Road Ditch ––Potential ImprovementPotential Improvement
Ditch enclosure to increase traffic safetyDitch enclosure to increase traffic safety
3 x 13 concrete box culvert3 x 13 concrete box culvert
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2,140 ft of roadside swale with raised 2,140 ft of roadside swale with raised
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inletsinlets
Cost Estimate: $2.5 M Cost Estimate: $2.5 M --$3.4 M$3.4 M
Includes excavation trench adjacent Includes excavation trench adjacent
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to Seminole Roadto Seminole Road
Includes dewatering and MOTIncludes dewatering and MOT
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Includes engineering and permittingIncludes engineering and permitting
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Other potential solutions could be Other potential solutions could be
considered: considered:
Regrade ditch and add retaining wallRegrade ditch and add retaining wall
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Additional outfall to Sherman Creek Additional outfall to Sherman Creek
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or the Sherman Creek Canalor the Sherman Creek Canal
Robert Street Ditch is owned by FDOT and the Robert Street Ditch is owned by FDOT and the
options available to the City are limited to north options available to the City are limited to north
of Dudley Streetof Dudley Street
FDOT:FDOT:
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Rehabilitation of existing ditch Rehabilitation of existing ditch
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Upsize of existing 30 inch pipe at Upsize of existing 30 inch pipe at
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Lewis Street to reduce peak Lewis Street to reduce peak
velocitiesvelocities
Atlantic BeachAtlantic Beach
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Potential upsize of existing 30 inch Potential upsize of existing 30 inch
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pipe at Dudley Streetpipe at Dudley Street
JacksonvilleJacksonville
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Maintain the portion of the ditch Maintain the portion of the ditch
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north of Dutton Island Roadnorth of Dutton Island Road
Robert Street Ditch Robert Street Ditch
CDM estimated a conceptual cost for a CDM estimated a conceptual cost for a
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typical ditch (500 ft long, 6 ft deep, and 35 typical ditch (500 ft long, 6 ft deep, and 35
Turf Reinforcement
ft wide)ft wide)
$5,000 ~ $10,000
Construction cost is highly dependent on Construction cost is highly dependent on
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site specific factorssite specific factors
T-Wall
$350,000 ~ $450,000
Metal Sheet Pile
Pipe + Swale
$420,000 ~ $580,000
$600,000 ~ $750,000
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Sea Level Rise ConsiderationsSea Level Rise Considerations
Potential Sea Level RisePotential Sea Level Rise
Uncertainty Uncertainty ––Different projectionsDifferent projections
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Projections include measured data Projections include measured data
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(NOAA), as well as 3 sea rise scenarios (NOAA), as well as 3 sea rise scenarios
based on USACE guidance based on USACE guidance
Support long term planning in low lying Support long term planning in low lying
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areas which may experience higher and areas which may experience higher and
more frequent tidesmore frequent tides
Projects should include corrosion Projects should include corrosion
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prevention measures to extend their prevention measures to extend their
useful lifeuseful life
City of Atlantic BeachCity of Atlantic Beach
Stormwater Master Plan UpdStormwater Master Plan Update
February 27 2012February 27 2012