Frequently Asked Questions
Over 10 years of operations, there has been extensive opportunity to study the Geotubes and their impact. You can find answers here to questions about how the Geotubes work, are maintained and studied, in addition to the process.
FAQs
What are Geotubes? Why does SBPF and the town of Nantucket want to extend the Geotube Project?
Know as “Geotubes” the system protecting ‘Sconset Bluff from further erosion is comprised of multiple geotextile tubes made from high strength, woven polypropylene sewn are covered with a thick cover of sand designed to erode during storm events and support the health of nearby beaches. During the now 10-years the pilot project protecting the most vulnerable section of ‘Sconset Bluff (and the nearby Baxter Road and its public infrastructure) has been effective at limiting impacts of erosion, without any significant or measurable impact on nearby beaches. Following up on a third-party study by respected coastal engineering experts at Arcadis, the Town of Nantucket formed a working group to recommend a path forward that protected town resources and individual homes by expanding the project. With several efforts to achieve this goal rejected by previous iterations of the Conservation Commission, the Town of Nantucket is now proceeding with a Notice of Intent to expand the project as originally anticipated.
Shouldn’t nature just take its course?
Due to the impacts of climate change, severe storms and overall sea level rise, erosion is indeed a way of life. But resiliency strategies are increasingly common to protect coastal areas, manage the impacts of sea level rise and create stability for the future. With the geotubes installation, we have a proven strategy with no downside environmental, recreational or community impact.
How do you know the Geotubes work?
Since the Geotubes were installed in January 2014, there has been zero erosion from the base of the bluff and no harm done to area beaches. With the addition of a storm water drain at the edge of Baxter Road, erosion from the top of the bluff has now also been stopped. American beachgrass planted on the face of the bluff has also helped reduce erosion caused by wind and rain. Leading coastal scientists conduct ongoing extensive monitoring and no negative impacts have been recorded.
Both SBPF and the town carefully monitor the sand covering the bluff, both in terms of the sand quality and to assure that there is enough to replace the sand that would have eroded from the unprotected bluff. There have been questions about sand quality due to some minor debris, but testing showed that the sand was safe. The amount of delivered sand exceeds the amounts normally required and is more than sufficient to replace the sand that would otherwise erode from the bluff, which is the whole point. All necessary protection is in place and working.
What role does the sand covering the Geotubes play?
The sand covering the Geotubes is designed to be washed away during storm surges and other high tide events, mimicking the natural erosion and movement of sand to other beaches. Often referred to as “sacrificial” sand, this model is designed to assure that nearby beaches face no unintended consequences from the Geotube installation.
Has SBPF met its obligations to maintain the sand covering the Geotubes?
Our initial application for the pilot project included a very conservative approach to sand replenishment, providing nearly twice the amount required and shown to be e ffective by other similar programs. SBPF was clear that we hoped to shift that model if the data proved that the initial volume of sand was more than what was required to achieve the goal of protecting nearby beaches.
For the vast majority of the history of the project, we met our sand obligations; however, we also consistently petitioned the Conservation Commission to allow us to reduce the amount of sand to a smaller, but effective amount. At two different points in the past three years – when it looked as though the project would not continue – we informed the town we would not be able to continue maintenance for a project that was likely to end. In Winter/Spring of 2022, we met our full obligations in anticipation of a compromise that would allow the full project to move forward. Unfortunately, that did not happen and in January of 2023 we told the town that we would no longer maintain the project.
While several recent storm events have exposed the Geotubes, this has happened in other challenging winter storm years with no measurable impact on nearby beaches.
Who pays for the Geotubes and their maintainence?
The Geotubes were installed and maintained by private citizens at no cost to the town. This included replenishing sand to meet required amounts, tracking/monitoring project impacts and reporting to the town and updating our model (for example, adding plantings to the protected section of the Bluff.)
What lessons have you learned in operating the Geotubes?
While this model had limited use in the region prior to our project, we have learned a great deal in the past 10 years:
The model is effective in protecting the Bluff, as well as adjacent homes, roadways and town infrastructure.
There have been no measurable impacts of significance on nearby beaches.
Access to ‘Sconset beach has not seen a significant impact.
The project is of great interest, with hundreds of residents and visitors learning about the project from our viewing area each year.
The amount of “sacrificial” sand placed on top of the Geotubes is significantly more than required to support nearby beaches.
If this project is so good for Nantucket, why did the previous conservation commission oppose expansion?
The initial agreement with the Select Board approving the pilot project created a path for expansion if the data showed that the project worked and had no negative impacts. Though the Conservation Commission has consistently denied our data driven updates and expansion requests, those denials have been overturned by the MA Department of Environmental Protection (DEP). As a result of various DEP rulings, the Geotube expansion has the legal right to move forward and sound data to show that expanding the project can occur without harm to nearby beaches. It is disappointing that members of the Conservation Commission and a small group of residents who do not believe that it is appropriate to manage the impacts of erosion have stopped us from moving forward. the independent review of this project by Arcadis reinforced what we have long known: the project works, it has zero negative impacts on others.
