Monroe County Pilot Roads Project Sands and Twin Lakes Communities

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1 Case Study in Roads Response Monroe County Pilot Roads Project Sands and Twin Lakes Communities Prepared for: Prepared By:

2 It s the End of the Road Overview of Report Recommendations for Pilot Communities Summary of Policy Response Interim Design Standard Draft Ordinance Resolutions for Consideration

3 Purpose of the Pilot Project Effort Address flooding impacts in two communities focused on road and stormwater improvements and develop alternatives to consider Twin Lakes Community Develop cost estimates for alternatives Develop a standard method to evaluate impacts for road improvement projects Create policies for road improvement projects countywide considering future flood impacts Sands Community Not final design, not final cost estimates countywide

4 Project Work to Date April 12 & 13 th - Kick off Meetings in Key Largo and Big Pine Public Meetings November 9 & 10 Public Meetings November 9 and 10 in Key Largo and Big Pine Collect data on historical flooding Part 1: Draft Report BOCC Briefing November 22 on Part 1: Alternatives Analyze future sea level rise projections Develop Cost Estimates BOCC Briefing December 14 on Part 2: Policy Response Develop scenarios (days flooded and levels) Develop design alternatives (elevation and stormwater) Final Presentation and Resolutions for Consideration

5 Report Contents Executive Summary Introduction Part I: Methodology and Technical Background Recommendations Part II: Legal and Policy Analysis Conclusions Appendices Appendix 1 Methodology for development of flood level estimates for the two communities Appendix 2 Draft Ordinance

6 Project Technical Assessment Process Hourly Water Level Vaca Key, Station Water Level, ft NAVD /1/16 12/31/14 12/31/13 1/1/12 1 Assess 20 Year Tidal Record and 2015 Event 12/31/12 12/31/10 12/31/09 1/1/08 12/31/08 12/31/06 12/31/05 1/1/04 12/31/04 12/31/02 12/31/01 1/1/00 12/31/00 12/31/98 12/31/97 12/31/96 1/1/ Incorporate Sea Level Rise Estimates 3 Develop Possible Design Scenarios and Estimate Costs 4 Assess Neighborhood Access Benefits for Investments

7 Roadway Elevation Twin Lakes Community Roadway Elevation Inches NAVD88 <

8 Roadway Elevation Sands Community Roadway Elevation Inches NAVD88 <

9 Design That Can Adapt to Changing Conditions It is possible to build to one future condition and adjust if conditions change; includes road bed and drainage system now but allows future elevation of pavement

10 Adaptive and Resilient Design for Stormwater Higher Groundwater Table from SLR will Limit Drainage Capacity of Soil in low-lying areas

11 Adaptive and Resilient Design for Stormwater Control Box Generator Higher Groundwater Table from SLR will Limit Drainage Capacity of Soil in low-lying areas

12 Implementation of Alternative Road/Stormwater Designs Local conditions may warrant different designs across the Keys (different elevations, different solutions) Team developed a summary of 6 conceptual stormwater design alternatives that considers: Suitability Constructability Maintenance Pros/Cons Engineering recommendation on feasibility Different types of road base may need to be considered (different materials or geogrids) Sharpe, Hakluyt Lane, Cudjoe October 2016

13 Technical Recommendations for Elevation Not to Exact Scale

14 Technical Recommendations for Elevation Inches NAVD 88 Mean Higher High Water Twin Lakes Community Sands Community Not to Exact Scale

15 Technical Recommendations for Elevation Inches NAVD 88 7 Days of Flooding Annually* Mean Higher High Water (+6 ) Twin Lakes Community Sands Community *Not to Exceed an Average of 7 Days of Flooding Annually Not to Exact Scale

16 Technical Recommendations for Elevation Inches NAVD 88 SLR to 2040 IPCC AR5 Median 7 Days of Flooding Annually* Mean Higher High Water (+5.4) (+6 ) Twin Lakes Community Sands Community *Not to Exceed an Average of 7 Days of Flooding Annually Not to Exact Scale

17 Design Alternatives for Community Response Design Scenario: Raise the Roadways to 5 of Elevation in Twin Lakes With Five Inches of Elevation Added to Lowest Roadway Points: Time Period Today 2040 Median SLR 2040 High SLR Impacts from the 2015 Event Return Period Conditions ROW Considerations Average =~ 4" =~ 9 Highest =~ 9" =~ 15" =~ 19" < 30 days =~ 1 < 7 days =~ 4 < 1 day =~ 3" =~ 7 No expected ROW needs Cost =~ $920K in Twin Lakes (at 6 ) Numbers Represent Water Depths on Improved Roadway

18 Design Alternatives for Community Response Design Scenario: Raise the Roadways to 11 of Elevation in the Sands Community With Eleven Inches of Elevation Added to Lowest Roadway Points: Time Period Today 2040 Median SLR 2040 High SLR Impacts from the 2015 Event Return Period Conditions ROW Considerations Average =~ 4" Highest =~ 5" =~ 11" =~ 15" < 30 days =~ 1 < 7 days =~ 4 < 1 day =~ 3 =~ 7 ROW may be needed Cost =~ $2.6M in the Sands Community (at 12 ) Numbers Represent Water Depths on Improved Roadway

19 Initial Results Conceptual Cost Estimates for Design Scenarios Twin Lakes Key Largo Sands Community Big Pine Elevation Length of Roadway Elevated Total Roadway and Drainage Cost Length of Roadway Elevated Total Roadway and Drainage Cost 6" 0.25 miles $0.92 million 0.3 miles $2.22 million 12" 0.7 miles $4 million 0.35 miles $2.63 million 18" 0.8 miles $5.8 million 1.3 miles $8.9 million 28" 0.9 miles $7.3 million 1.5 miles $10.5 million Costs factored in: Maintenance of traffic, mobilization, design, construction, 15% of costs for construction engineering and inspection, 25% contingency and stormwater features. Costs not factored in: right-of-way (~12 is threshold), driveway improvements

20 Policy Approach Interim Standard Ordinance Countywide Analysis

21 Appendix 1: Road Design Methodology Appendix 1 narratively describes the steps in the process so they can be applied in other areas Tidal datum based on current tidal epoch MHHW (NAVD88) Elevation addition to not exceed 7 days of flooding annually based on 2015 sea level Sea level rise Resulting estimate target using IPCC minimum AR5 Median elevation for (2015 to 2040) roads (2040)** (NAVD88) Sands Community Twin Lakes Community The negative values are in relation to the NAVD88 datum, where zero is a point approximately equal to the low point of the roadways in the two communities.

22 Appendix 2: Draft Ordinance 1. Describes Design Methodology from Appendix 1 and adopts it as standard to determine elevations for new road improvement projects 2. Evaluate/analyze local conditions 3. If the design criteria cannot be met for a road improvement project, or if the criteria can be met, but the local conditions analysis shows that it would not be economically or environmentally practical to meet it, the County may designate the Improved Road to be an Environmentally Challenging Location. 4. Defines conditions that impact meaningful access (flooding, limits on vehicle access or lanes may be closed or impacted)

23 Draft Ordinance Process Flow for Road Design Sea Level Rise Determine project life (Year: ie, ) Incorporate Median or Low sea level rise projection and not to exceed duration (30, 7 or 1) Local Factors Evaluation Existing and future conditions Environmental Considerations Space Considerations Impact Evaluation Decision: Can Road Meet Median or Low Sea Level Rise Projection with Design Criteria? Special Designation for Environmentally Challenging Locations Identify which local factors are problematic Identify how design criteria will differ Meaningful Access Determination Determine the types of access issues Present to Board of County Commissioners If no, further evaluation If Yes, Design Criteria Evaluation Complete

24 Local Conditions Analysis/Evaluation Physical site constraints; Current road conditions and elevations; Current elevation of adjacent properties; Sensitivity of the land or mitigation requirements to be met; Water quality requirements; Right of way needs; Availability of land to accommodate drainage; Elevation of water table in relation to road elevation; Impacts to access for private property (driveways); Future maintenance needs and costs including staffing requirements; and Number of developed properties that the subject road services as the sole means of access.

25 Implementation Considerations LOCAL CONDITIONS AFFECTING FINAL DESIGN RECOMMENDATIONS Sensitive Lands / Mitigation Roadway Elevation & Condition Adjacent Property Elevation Future Sea Level Rise Driveway Access Space for Drainage Improvements ROW Requirements Elevation of Water Table Water Quality Requirements For Permitting Electrical And Water/Sewer Utilities Stormwater System Maintenance Costs Including Staff

26 Pilot Roads Project: One Piece of the Puzzle County awarded competitive bid for improved elevation data (LIDAR) County launching grant from NOAA to run new hazard models to better define threats from SLR and surge (can potentially run other scenarios needed for CRS) Grant applications to do sea level rise planning on certain at-risk facilities (Bayshore Manor & Harry Harris) Countywide roads analysis in the next year to identify priorities based on timeframe of vulnerability ( road miles at risk by 2030) Starting to incorporate SLR considerations in capital improvements Adopting policy for specific criteria in road projects

27 Resolution #1: Approve Final Report and Move Forward with Pilot Communities Design The Board of County Commissioners shall approve the Final Report for the Monroe County Pilot Roads Project: The Sands and Twin Lakes Communities. The Board of County Commissioners hereby directs staff to budget funds in the FY17/18 budget and to move forward with the design phase to implement the Recommendations included under Section 4.5 of the Final Report for the Monroe County Pilot Roads Project: The Sands and Twin Lakes Communities. Raise to final elevation of 5 for Key Largo and 11 for Big Pine Estimated cost of design $400,000-$450,000 (only budget item in Resolution, not construction at this time) Construction for 6 and 12 was estimated at $3.55 Million Russo, Crane, October 2016

28 Resolution #2: Adopt Interim Road Design Standard and Undertake Countywide Roads Analysis Appendix 1 Methodology from the Final Report for the Monroe County Pilot Roads Project: The Sands and Twin Lakes Communities will serve as an appropriate Interim Standard (not > 7 days tidal flooding + Median SLR by project year) for determining the elevation of road improvement project until a Revised Standard is developed in the future. Move forward with a Countywide Roads Analysis project to identify near-term roads subject to inundation risk, including nuisance flooding. The Board of County Commissioners hereby directs staff to budget funds in the FY17/18 budget for the Countywide Roads Analysis project. GreenKeys Plan estimated $1.0 to $1.5 Million for project in 5 Year Work Plan King Avenue, Key Largo Rodriguez, 10/14/16

29 Thank You