Broad Beach Sand & Dune Habitat Restoration Project Broad Beach Revetment Owners August 29, 2015.

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Transcript of Broad Beach Sand & Dune Habitat Restoration Project Broad Beach Revetment Owners August 29, 2015.

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”