HomeMy WebLinkAboutPresentation 9.19.20241
09/19/2024
Great Island Homeowners
Association – NOI for Dune
Restoration and
Maintenance Along Great
Island Road
New Design Addresses Commissions Concerns for South Section
Remove geotextile bags along South
section where sand cover has been
difficult to maintain.
New design includes:
-Array of 4 fiber rolls
-Sand from bulk bags compacted
and placed between road and fiber
rolls
-Fiber rolls secured with steel cables
and duckbill anchors
-Cover fiber roll array with sand and
plant with beach grass
110 ft
810 ft
Schedule, Construction Access, Resource Area Impacts
Schedule for Construction:
-Fall 2024
-Beneficial reuse of sediment
dredged from Sweetwater Creek for
sand cover
Construction Access:
-Identical to access used for
installation of geotextile bags
Resource Area Impacts:
-110 ft of shoreline
-2,031 sq ft coastal dune
-2,047 sq ft coastal beach
-All resources previously impacted
during geotextile bag installation
Future Work
If necessary, restore dune in North
and South sections twice annually
with up to 2,090 cy of compatible
sediment.
-Regular inspections of sand cover
by GIHA staff
-Post storm inspections by Woods
Hole Group
Damaged geotextile bags in north
section to be replaced with fiber rolls
as necessary
- Notices to Cons Comm if geotextile
bags are replaced and prior to sand
placement
MA DMF Comments
TOY restriction for all beach work
Nourishment consistent with
MassDEP Beach Nourishment
Guidelines
Planting and restoration plan for
dunes
Pre- and post-construction eelgrass
monitoring plan
Modeling of cross-shore sediment
transport
No equipment in intertidal zone
Containment materials on site for
refueling of equipment
Recommended Conditions
1.Visual monitoring of sand bags & fiber roll array monthly.
2.Inspect sand bags & fiber roll array following storms with report/photos to Conservation
Commission.
3.Keep sand bags & fiber rolls covered with sand with up to 2,090 cy of beach compatible
sand twice annually.
4.Notify Conservation Commission in advance of dune nourishment activity and follow up
with report to Commission.
5.Dune nourishment to occur before March 1 and after August 31.
6.If bags become damaged they will be removed immediately to prevent loss of geotextile
fabric into the coastal environment.
7.Replacement of existing sand bags with new geotextile bags is not allowed.
GIHA Resiliency Planning
Feasibility Study Recommendations for Long-Term Resiliency
Near-Term (1-5 years):
-File proactive NOI for emergency roadway protection, as needed based on dune erosion
-Fiber rolls, sand cover & beach grass plantings similar to current proposal for South section
-Protects roadway from damage caused by erosion until long-term plan can be implemented
Mid- to Long Term (5-50 years):
-Raise sections of road to 4.5 ft NAVD88 & reconstruct bridge
-Relocate & raise sections of road to 7.5 ft NAVD88 & reconstruct bridge
-Selection of preferred approach by GIHA, design, permitting & construction will take ~ 5 years