broad beach sand & dune habitat restoration project broad beach revetment owners august 29, 2015
TRANSCRIPT
Broad Beach Sand & Dune Habitat Restoration Project
Broad Beach Revetment OwnersAugust 29, 2015
Proposed Broad Beach Restoration
MISSION:1. Restore historically wide beach by adding sand and restoring dune habitat 2. Maintain buried permanent revetment for future storm protection.
Alternative 4C Highlights- Project Footprint: No nourishment west of 31380
Broad Beach Road
- Revetment Alignment: Affects 30760-30978 BB Rd
- Revised Dune Plan: 3:1 ratio of dunes restored to dunes impacted
- Septic Feasibility Study: Complete w/in 3 yrs of CDP
- Backpassing & Nourishment Triggers: Avoid lateral access easements
- Comprehensive Monitoring Plan & Science Advisory Panel: BBGHAD & CCC to share management
- Requested 20 year term: 10 yr + extension?
Project Update
• Post 12/14: Extensive meetings with senior regulatory staff members
• Progress: overall Project concept, west end nourishment, revetment location and entitlement; sand source, spec, and logistics
• Alternative 4C: submitted 4/15
• CCC hearing: anticipated 10/15
• Army Corps & others: approx Fall 2015
• Proposed Construction Start: Early 2016?
Beach Restoration: Photo Simulation- West
Beach Restoration: Photo Simulation- Central
Beach Restoration: Photo Simulation- Central from 31048
Beach Restoration: Photo Simulation- East
Typical Proposed Beach & Dune Cross Sections
31324 Broad Beach Road
30916 Broad Beach Road
Revetment Realignment – 30760 to 30968
• Pullback contemplated since 2010 ECDP• BBGHAD contested & negotiated pullback mandated by CCC/
other agencies• Realignment may alter certain backyard improvements
Revetment Realignment- updated 8/28/15
Post Construction Condition Eastern End of Revetment
Pulled Back Revetment Covered with Dune Plants
Nourished Beach
Final dune design subject to approved dune restoration plan
Existing Condition
Existing 2010 Revetment
As shown: 30860 Broad Beach Rd.
BBGHAD Proposed RevetmentPullback
Nourished Beach Condition
Pulled Back Revetment Covered with Dune Plants
Nourished Beach
Existing Leach Fields
Future Leach Field
Final dune design subject to approved dune restoration plan
As shown:30860 Broad Beach Rd.
BBGHAD Proposed RevetmentPullback
Nourished Beach Condition
Pulled Back Revetment Covered with Dune Plants
Nourished Beach
Existing Leach Fields
Future Leach Fields
Final dune design subject to approved dune restoration plan
As shown: 30866 Broad Beach Rd.
BBGHAD Proposed Revetment Pullback
Nourished Beach Condition
Pulled Back Revetment Covered with Dune Plants
Nourished Beach
Existing Leach Fields
Future Leach Fields
Final dune design subject to approved dune restoration plan
As shown: 30952 Broad Beach Rd.
BBGHAD Proposed RevetmentPullback
Nourished Beach Condition
Pulled Back Revetment Covered with Dune Plants
Nourished Beach
Existing Leach Fields
Future Leach Fields
As shown: 31022 Broad Beach Rd.
Final dune design subject to approved dune restoration plan
Alternative 4C: Proposed Dune Footprint: West to Middle Area
Alternative 4C: Proposed Dune Footprint: Middle to East End
West End Nourishment Limitation
• Ends nourishment at 31380 Broad Beach Rd.• Preserves “boulder field” between 31444 and 31380• Limits depth of cover to approximately natural conditions west of
31380
Boulder Field
31380
West End Sensitive Marine Resources31380 Broad Beach Rd
21
Summary of West End Analyses
GOAL 1: Natural sedimentation levels determined- Spring accumulation varies up to 3 feet
- Fall accumulation up to 5 feet
GOAL 2: Project-related sand transport & burial determined- 3D mapping used to quantify Project burial exceeding natural levels
GOAL 3: Impacts to sensitive resources analyzed - No predicted impact to eelgrass and kelp
- Impacts to surfgrass predicted to be less than significant
- Impacts to lower intertidal boulder field predicted to be less than significant
- As expected, beach nourishment project adds sand to upper intertidal and sandy habitats
Septic System Study
Proposed Compromise:
• 2 years after CDP becomes effective
• Implementation based on findings: 6+ yrs
Proposed Backpassing & Renourishment TriggersActivity Triggered when…
Backpassing • West end beach less than 75’ for 3 months and sufficient sand at east end to backpass: likely 1-2x per 5 years
Interim Nourishment
• West end beach less than 30’ for 6 months• Add up to 75,000 cy: proposed assessment funds no more than 3
per 5 yrs.• Avoid summer placement• Discretionary
Erosion Nourishment
• Less that 10’ dry beach width fronting revetment• Place at least 75,000 cy / avoid summer placement• Not discretionary – GHAD commits to keep minimum 10’ beach
width fronting revetment instead of providing lateral access easements landward of revetment
• Maximum 3 erosion nourishments within 10-yr period
BBGHAD’s Proposed Monitoring
• Resource Monitoring During Construction• Adaptive Management and Monitoring• Dune Habitat Restoration and Monitoring Plan• Long-term Marine Resources Monitoring, Reporting, and
Mitigation Plan• Public Access Management Program• Science Advisory Panel ("SAP“) • Cost: Approximately $3M/10 years
Beach Width Monitoring “Transects”
Primary Remaining Issues With CCC
1. Revetment Alignment & Duration
2. Dune footprint
3. Scope of public/lateral access
4. Permit term
5. SAP Details
6. Sand specification
Moving Forward
1. Revised Engineer’s Report- Board adopted July 2015; Resolution No. 2015/03
2. Proposed New Assessment: $595/linear foot; 25% for those west of 31380
3. Property Owners’ vote on new assessment: ends 9/6/15 at 9:00 a.m.
4. Construction Schedule: Early 2016?
END
Predicted Westward Sand TransportAfter 75,000 cy “Interim Nourishment”