Nicole Elko, Ph.D. September 20, 2013 FBCP DUNE MANAGEMENT PLAN

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1 Nicole Elko, Ph.D. September 20, 2013 FBCP DUNE MANAGEMENT PLAN 1

2 OUTLINE Introduction Folly Beach County Park (FBCP) 2013 Renourishment Stabilization Project Dune Management Plan Purpose USACE Folly Beach Periodic Renourishment Existing Conditions Three Beach Segments + Marsh side Management Plan Goals Objectives & Recommendations Dune Fencing/Vegetation Planting Plans Implementation Plan Discussion 2

3 INTRODUCTION: FOLLY BEACH COUNTY PARK 3

4 FBCP RENOURISHMENT PROJECT June ,000 cubic yards Up to 500 ft berm 745 ft Terminal Groin Gravel Road $3.46M 65% sand 35% structure 4

5 DUNE MANAGEMENT PLAN (DMP) PURPOSE Restore a natural dune ecosystem Plan before act DMP: Flexible nature s dynamics & changing user needs Mitigate and adapt to future erosion and sea level rise challenges Informed decision making based on scientific data (long-term) 5

6 US ARMY CORPS OF ENGINEERS 6

7 EXISTING CONDITIONS

8 SEGMENT 1: ENTRANCE 3 Access Points: 1 Vehicle 2 Pedestrian #1 = Pelican Watch WALKOVER 8

9 SEGMENT 2: CENTRAL 4 Access Points: 1 Vehicle 3 Pedestrian

10 PORT-O-LET LOCATIONS SOUTHWEST Wind Direction NORTHEAST 10

11 SAND FENCING ORIENTATION Wind Direction 11

12 DOWNDRIFT CENTRAL 12

13 SEGMENT 3: DOWNDRIFT 1 Vehicle Access 13

14 MARSH SIDE 14

15 CCPRC GOALS Re-establish a natural dune ecosystem Adhere to DHEC-OCRM Permit G Retain nourished sand on beach side of road Mimic nature Locate dunes in long-term stable portion of backbeach Provide public access while building dunes year round Follow integrated plan for park management decisions 15

16 RE-ESTABLISH NATURAL DUNE ECOSYSTEM Objectives: Restore robust, vegetated dunes (short-term) Maritime forest (long-term) Attract native fauna with native flora Mimic natural land elevations Retain open space for shorebirds on marsh Limit high elevations nearby GOAL #1 16

17 RE-ESTABLISH NATURAL DUNE ECOSYSTEM Recommendations: Plan to restore a different dune system than existed previously (modify your expectations) Allow overwash deposit to evolve naturally GOAL #1 Avoid predator enhancements: No sand fence or sea oats on marsh-side of road (limit elevations) Plant creeping and scrub vegetation to stabilize marsh-side of road mimic adjacent areas. 17

18 CCPRC GOALS Re-establish a natural dune ecosystem Adhere to DHEC-OCRM Permit G Retain nourished sand on beach side of road Mimic nature Locate dunes in long-term stable portion of backbeach Provide public access while building dunes year round Follow integrated plan for park management decisions 18

19 GOAL #2 ADHERE TO DHEC-OCRM PERMIT Objectives: Specific Condition #19: All planting must be designed to minimize impacts to sea turtles Specific Condition #20: New beach access locations must be approved by the Service and OCRM Specific Condition #21: Expanded or newly created beach access points must be restored to dune habitat within 3 months following project completion. Habitat restoration must consist of restoring dune topography and planting with appropriate native dune vegetation. Advance/proactive mitigation downdrift of the terminal groin 19

20 GOAL #2 ADHERE TO DHEC-OCRM PERMIT Recommendations: Limit continuous, shore-parallel, sand fencing to landward of future dune crest Engage DHEC OCRM and USF&WS staff in dune management meetings Restore and stabilize dune in downdrift segment 20

21 CCPRC GOALS Re-establish a natural dune ecosystem Adhere to DHEC-OCRM Permit G Retain nourished sand on beach side of road Mimic nature Locate dunes in long-term stable portion of backbeach Provide public access while building dunes year round Follow integrated plan for park management decisions 21

22 RETAIN SAND ON BEACH SIDE OF ROAD Objectives: Protect investment in new road with green infrastructure Limit parking lot maintenance Limit sand entering marsh & limit runoff from road to marsh GOAL #3 22

23 RETAIN SAND ON BEACH SIDE OF ROAD Recommendations: Restore dune system into a continuous line of defense Locate dunes as close to road as possible Stabilize marsh-side of road with creeping and scrub vegetation (bacharius) GOAL #3 23

24 CCPRC GOALS Re-establish a natural dune ecosystem Adhere to DHEC-OCRM Permit G Retain nourished sand on beach side of road Mimic nature Locate dunes in long-term stable portion of backbeach Provide public access while building dunes year round Follow integrated plan for park management decisions 24

25 LOCATE DUNES IN STABLE PORTION OF BEACH Objectives: Create largest (primary) dunes as far landward as possible Provide at least 75 ft of beach area for public use Avoid dune erosion GOAL #4 25

26 LOCATE DUNES IN STABLE PORTION OF BEACH Recommendations: GOAL #4 Cite future toe of dune at least 100 ft landward of equilibrium shoreline Utilize planting and fencing design that becomes less aggressive toward the ocean 26

27 CCPRC GOALS Re-establish a natural dune ecosystem Adhere to DHEC-OCRM Permit G Retain nourished sand on beach side of road Mimic nature Locate dunes in long-term stable portion of backbeach Provide public access while building dunes year round Follow integrated plan for park management decisions 27

28 PROVIDE PUBLIC ACCESS & BUILD DUNES Objectives: Build dunes and provide access in peak summer season for beach users Build elevation inside access paths during off season, peak wind season Year-round dune building Minimize breaks in dune system that could funnel storm surge Keep users out of establishing dunes Provide vehicular access where necessary GOAL #5 28

29 PROVIDE PUBLIC ACCESS & BUILD DUNES This Not This 29

30 GOAL #5 PROVIDE PUBLIC ACCESS & BUILD DUNES Recommendations: Minimize access points Angle/slant paths north-south Close some access paths in off season Install temporary sand fencing if possible Relocate port-o-lets to NE side of access paths Utilize continuous sand fencing to build dunes and control pedestrian traffic Along paths and at dune/parking area transition Limit continuous, shore-parallel, sand fencing to landward of future dune crest Compare post-project turtle nesting data with planned fence lines 30

31 PROVIDE PUBLIC ACCESS & BUILD DUNES Recommendations (cont.): Two vehicle access points at each end of park North vehicle access to be phased out South vehicle access wide enough for vehicles Including tilling equipment and bulldozers for future maintenance One vehicle access at south end to provide access around the terminal groin GOAL #5 31

32 CCPRC GOALS Re-establish a natural dune ecosystem Adhere to DHEC-OCRM Permit G Retain nourished sand on beach side of road Mimic nature Locate dunes in long-term stable portion of backbeach Provide public access while building dunes year round Follow integrated plan for park management decisions 32

33 GOAL #6 INTEGRATED PLAN FOR MANAGEMENT DECISIONS Objectives: Determine fate of maintenance material from new road (sand/gravel mixture) Minimalist beach access approach Paths & natural materials vs. boardwalks, platforms Minimize storm debris & maintenance Create Beach-side Public Use Area Volleyball courts and staging area for ecotours/events Potential for future facility citing Designate new location for lifeguard station Consolidate signage into educational displays Define needs of three park segments 33

34 EVIDENCE FOR MINIMALIST APPROACH Dunes overtaking wooden structures Maintenance issues 34

35 INTEGRATED PLAN FOR MANAGEMENT DECISIONS Recommendations: GOAL #6 Deposit sand/gravel from maintenance at south end vehicle access to create stable road pad Do not construct walkovers until dune system and user needs have been well established Utilize and properly maintain Mobimats for handicapped access Avoid wooden shower platforms that can be inundated with sand utilize natural gravel bases Relocate existing shower/platform farther landward Avoid platforms for Port-o-lets Smooth sand base and re-adjust if needed 35

36 INTEGRATED PLAN FOR MANAGEMENT DECISIONS Recommendations: Cite public use area in long-term stable location behind dunes = Adjacent to terminal groin Replicate natural dune/swale environment Stabilize use area with creeping vegetation if needed Limit sand loss into parking lot with creation of small dune (vegetation/fencing) 10 off bollards Erect temporary shade when needed GOAL #6 36

37 NATURAL DUNE/SWALE ENVIRONMENT 37

38 INTEGRATED PLAN FOR MANAGEMENT DECISIONS Recommendations: GOAL #6 Relocate existing lifeguard station Downsize width of first vehicle access to pedestrian Favor long-term stability and most hazardous swimming conditions = near terminal groin Install water line on beach side of road Plan for future infrastructure Potential utility corridor on marsh side Compile all anticipated signage Design educational displays in 1 year 38

39 CCPRC GOALS Re-establish a natural dune ecosystem Adhere to DHEC-OCRM Permit G Retain nourished sand on beach side of road Mimic nature Locate dunes in long-term stable portion of backbeach Provide public access while building dunes year round Follow integrated plan for park management decisions 39

40 EDUCATIONAL & REGULATORY SIGNAGE 40

41 SIGN POLLUTION 41

42 EXAMPLES: KEEP OFF DUNES SIGNS 42

43 OVERVIEW Public Use Area Toe of Dune (Keep Out) 43

44 DUNE MANAGEMENT PLAN: OVERVIEW Beach Access Sand Fencing Dune Vegetation Public Use Area Toe of Dune (Keep Out)

45 DUNE FENCING PLAN: TRAFFIC MGMT Beach Access Sand Fencing (continuous) Toe of Dune (Keep Out)

46 DUNE VEGETATION & FENCING PLAN: DETAIL Dune Vegetation: Sea oats (70%) Bitter panicum (30%) Beach Access Sand Fencing Dune Vegetation Toe of Dune (Keep Out) 46

47 DOWNDRIFT Sand Fencing Dune & Creeping Vegetation Toe of Dune (Keep Out) Dune Vegetation: Sea oats Bitter panicum Vines (ipomoea) 47

48 MARSH SIDE No Sand Fencing Creeping & Scrub Vegetation Keep Out Vegetation: Salt myrtle Marsh elder Vines (ipomoea) 48

49 NEW ACCESS SPECIFICATIONS Design for summer wind conditions Correspond with high-use season Based on today s on-the-ground conditions Relocate Port-o-lets to northeast side of paths Reorient path angle away from shore perpendicular Slanted paths Orient dune fencing shore perpendicular Water line on seaward side of road 49

50 RECOMMENDED IMPLEMENTATION PLAN Initial construction before May 1, 2014 Install water line on beach side of road to terminal groin Provide for temporary irrigation system for dunes Install sand fencing ASAP Install keep out post & ropes Plant all recommended vegetation (after water line) before October 15 or after March 15 Relocate port-o-lets and shower platform 50

51 RECOMMENDED IMPLEMENTATION PLAN Phase II Assess vegetation and fencing performance Adjust fencing patterns as needed Plant additional vegetation as needed Plant palms at beach access points Design & install educational signage Showers 51

52 DISCUSSION 52