Below, please find both questions asked regarding the Causeway project in addition to video of John Ramsey’s presentation.
Q&A from John Ramsey (ACE, Inc.) prior to the 8.6.2020 Site Visit
Do we have design drawings and cross-sections for the Town projects, and are the designs the same from south to north?
We have the drawings, but that project is different from the work proposed for your Association. For the Town section, an existing concrete seawall backs the revetment. The design is the same from south to north
Did the design engineer(s) recommend a maintenance program for these sections?
No, the Town has a difficult time setting aside maintenance funds from a budgetary perspective
The work currently underway in front of DJ’s house [203 Chapoquoit Road] uses different boulders than those used in the section closer to the public beach and elsewhere in the region for that matter. Is this a purposeful decision or possibly a low-bid modification of the design spec.?
There has been no change in the design
How well has the southernmost repair performed since it was completed, and what is the Town’s planned/budgeted maintenance program?
The repair has performed well. Maintenance is discussed above.
The recommended maintenance was periodic re-chinking with larger rocks than the 1-2″ stone used to fill after storms, as discussed and budgeted during the last annual meeting. This was intended to stabilize the large, angular boulders and slow erosion by wave action behind the seawall. Why wasn’t this maintenance completed as planned?
As we were not involved with the previous design, we cannot comment on this in detail other than to indicate that depending on “chinking” for revetment stability is not generally useful in an active wave environment. The updated revetment will utilize larger stones that do not need to be chinked.
This will most likely be a century-long, losing battle, so we should plan to monitor and maintain in the near-term, and harbor our resources for the long-term. What does the “master plan” look like and how do we avoid over- or under-spending scenarios?
This is outside our scope right now, but any coastal structure will require maintenance at some point. The goal here is to establish more robust shore protection that will have a longer design life and protect the island access and utilities to a greater extent than the existing structure
Is installation of sheet piling between the seawall and the asphalt surface a viable next step, with spot repair of erosion or voids discovered during installation? The seawall and roadway look to be in good shape, and there is no visible evidence of voids similar to those that developed over several years along the Town sections. The recent GPS survey indicated small areas of erosion on the seaward edge, but nothing warranting the level of disassembly and reconstruction required along the Town section.
The Town section is different as described above. Steel sheeting will provide stability for the roadway and prevent potential future “washouts.”
Do one or more of the waterfront owners north of the seawall intend to armor their shorelines around the point to Big Pier? Is this feasible and/or advisable and, if so, is there an opportunity for the Town, the Association, and these households to get aligned around a long-term master plan for the causeway and Chapoquoit Point?
Again, this is out of our present scope, but it should be noted that armoring dunes likely would not be allowed under environmental regulations.
Finally, I assume the metal railing spec’d for the public road is not a requirement for the Association section, and an opportunity for cost saving in any future reconstruction project? Are there other opportunities for value engineering and cost savings?
The proposed plan calls for a concrete cap on top of the sheet pile that will extend the wall height 2-2.5 feet above the road to improv coastal resiliency. This will serve as a guardrail. We plan to perform test borings to ensure a future contractor knows the types of soils they will encounter. This approach usually avoids any change orders and/or design modifications which can be costly.
What objectives, specifically, have the Trustees given the engineer for the causeway project?
The design is looking down the road 30 to 50 years.
I understand the stated, overall objective is to protect the causeway, but what does that mean specifically?
Stabilize the roadway, even under severe storm conditions. The goal here is to establish more robust shore protection that will have a longer design life and protect the island access and utilities to a greater extent than the existing structure. Specifically, improving concerns related to storm wave overtopping and potential breaches of the roadway during storms.
For instance, Is there an expectation that the project will prevent all damage to the road in a storm like Carol or Bob? Or is the objective more modest?
It will prevent formation of a breach through the roadway, but some pavement damage will occur during storms where the water level rises above the road. Not really modest, but dealing with the relatively frequent storms is a reasonable goal. Attempting to preserve a road directly on the coastal from all potential storm events is unrealistic
It was mentioned in the Annual Meeting (July, 2020) that the causeway would be raised. That could be a solution to a problem, but what, exactly, is the problem that it would solve and would it really solve it?
The cap will be raised to reduce wave overtopping now and in the future. This condition is expected to get worse as the beach continues to lower and sea level continues to increase.
In what way will the proposed project provide better protection than the current revetment, which was restored in 2014?
It will provide improved protection. Larger armor stones will not move as readily and not require chinking for stability. Deeper excavated toe stones will ensure that continued beach lowering will not impact the stability of the revetment. The sheet pile and concrete cap will (a) prevent any washout of the roadway during storms, and (b) reduce any potential damage caused by storm wave overtopping.
Do you expect the Con Com to require regrading the road so that it drains away from the beach as it did for the Town’s project to the south? If so, how will that be accomplished?
No, but we typically would incorporate this approach in the design. This can be accomplished easily because of the new concrete cap at the landward edge of the road.
My understanding from the Annual Meeting is that the current Town project to the south was designed by the engineer who is consulting to the Trustees. Why is the design for that project different from the two previous phases of the repair to the causeway south of the Island?
It is not.
Would the engineer consider the contractor on the Town’s project for our project?
We would consider all qualified contractors