Loading...
HomeMy WebLinkAbout2018-3-28Minutes for March 28 2018 adopted Apr. 11 CONSERVATION COMMISSION SPECIAL HEARING 2 Bathing Beach Road Nantucket, Massachusetts 02554 www.nantucket-ma.gov Wednesday, March 28, 2018 0 4 Fairgrounds Road, Community Room - 4:00 P.M. cza Commissioners: Andrew Bennett (Chair), Ashley Erisman (Vice chair), Ernie Steinauer, David LaFleurr Ben Champoux, Ian Golding, Joe Topham �o Called to order at 4:00 p.m. J Staff in attendance: Jeff Carlson, Natural Resources Coordinator, Terry Norton, Town Minutes Taker a Attending Members: Bennett, Erisman, Champoux, Golding, Topham Remote Participation: Per 940 CMR 29. 10, Golding is participating remotely due to distance. 9 Absent Members: Steinauer, LaFleur c - Late Arrivals: None v' Earlier Departure: None Agenda adopted by unanimous consent *Matter has not been heard I. PUBLIC MEETING A. Public Comment — None B. Annual report presentation and discussion Sconset Beach Preservation Fund — 87-105 Baxter Road Area (multiple parcels) SE48-2824 Sitting Bennett, Erisman, Champoux, Golding, Topham Recused None Documentation SE48-2824 2017 Annual Review; `Sconset Sand Delivery Report Jan 2018 revised 1.23.18; `Sconset Sep -Dec 2017 Work Reports 2017 Annual Review Peer Review. Applicant Josh Posner, 77 Baxter Road, Chairman'Sconset Beach Preservation Fund (SBPF) Representatives Stephen Cohen, Cohen & Cohen LP Maria Hartnett, Epsilon Associates Inc. Jamie Feeley, Construction Manager Cottage and Castle Inc Arthur D. Gasbarro, Nantucket Engineering & Survey Public Dirk Roggeveen, for Quidnet/Squam Association (QSA) Judith Wegner, 50 Quidnet Road Emily Molden, Nantucket Land Council (NCL) Hugh Ruthven, III Applied Coastal Research and Engineering (ACRE) D. Anne Atherton, Nantucket Coastal Conservancy Discussion Carson — Reminded everyone that this is in regard to the annual report of the existing 947 -foot structure. Posner — Provided an update on the issue of sand delivery for the mitigation which is to mimic natural erosion and the sustainability of using local sand pits; about 1500-2000 dump truck loads a year. Alternate sand sources reviewed: mining off -shore sand, from Polpis Harbor, barging from the mainland, and other upland sources. Regulation of the source of sand and use of the roadway for delivery is outside ConCom jurisdiction but a matter for the Select Board; SBPF has proposed to Select Board that condition of their issuance of a license to move forward once the permit is issued. Cohen — Reviewed the history of SBPF since 2013 leading to the application for the geotube structure. This is the second annual report for 2017; the first report covered 2015 to 2016. This report indicates, and concurred by the peer review, that the structure is working as designed with no adverse impact and created data points that will allow for refinement of the project. Ms Hartnett will cover three times in her presentation: the report itself, responses to questions and comments, sets of failure criteria laid out in the Order of Conditions, and suggestions for improvements. Hartnett — With five years of information, there is considerable data available; reviewed the data collected and laid out in the report and the independent reviewer's comments: the toe of the bluff has been stabilized; pleased with the revegetation of the top of the bluff; not seeing adverse affect to underwater and wetland monitoring; no change in the shape of the beach. Reviewed location of ground control points used for the surveys. Compared to the 2013 photogrammetry survey, the bluff is stable; we noted an average of about 5.8 feet of erosion of the unprotected bluff. The geotube area has contributed about 15.5 cubic yards (CI) per year while the unprotected area contributed about 5.8 CY per year. Responded to independent review comments: request for additional parameters to increase accuracy; results of monitoring of shoreline for erosion; and stability of the mean high -tide and mean low -tide water lines. Reviewed the sand -delivery reports and responded to independent -review comments and questions on whether or not more sand should be delivered. Reviewed the results of monitoring the wetland wells: water levels are not different from historic levels. Reviewed off -shore transect results: no significant change in the off -shore cobble habitat; independent Page 1 of 3 March 28, 2018, adopted Apr. 11 reviewer suggested an additional review method to monitor invertebrates; we will take that into consideration. Reviewed success of the over -the -bluff stormwater run-off mitigation measures. Reviewed requested changes in monitoring as outlined the Order of Conditions: reducing the frequency of shoreline profile monitoring; underwater video monitoring to eliminate the need for a swimmer and reduce frequency, have Department of Public Works (DPW) take over the drainage monitoring; reduce the amount of sand to the template to 14.3 CY per year and when the sand is delivered; access to the top of the geotubes for sand delivery trucks. Pointed out that detailed information about the 2018 March storms will be covered in the 2018 annual report; reviewed damage from the March storms and post -storm actions. Stated that hardener had to be added to stabilize the vehicle access ramp at Hoicks Hollow. Responded to comments from Nantucket Land Council (NLC) and the Nantucket Coastal Conservancy (NCC); some comments and concerns were addressed in discussion about independent review comments. Conclusion: tubes stabilized the base of the bluff and area supplies about twice as much sand. Bennett — Doesn't understand why there is more end scour at the north end and why the end is different than the south end. Feeley — The south end return are longer and more gradual; the north end was made shorter and sharper to tie into the clay head. Erisman — The geo-tube sticks out farther than the toe of the unprotected bluff and will absorb wave energy first and the beach in front of the unprotected bluff is lower than in front of the geo-tubes; there will be a point at which that beach can't drop any more. The sand in front of the unprotected section is unconsolidated sand so washes away more easily. Hartnett — Pointed out that the sand moves back and forth and the beach rises and falls as the sand is moved and that the beach in front of the tubes drops as well. Erisman — In regards to Storm Function, she wants to know where sand is coming from, where the sand is going, how much is lost when the template isn't covered. Cohen — The availability of sand during a storm is a different question from the net contribution. Erisman — Asked if there is any way to quantify the amount of sand (not contributed to the littoral system) when tubes are uncovered during and after a storm event. Hartnett — They are noticing a pattern of sand drift. Erisman — Asked about the thick plastic she noticed during the site visit Feeley — That is to direct water out from between the tubes away from the bluff; all that was covered in the construction methodology of the initial hearings. Bennett — Asked if there had been any inspection to determine whether or not any of the tubes themselves have slumped. Feeley — He has not noticed any slumping tubes during his review of the structure after it was exposed. Bennett — In regards to the shoreline survey and since they are done during different times of year, asked how the natural beach profile is factored in. Hartnett — They are trying to capture the overall, long-term affect and look at the beach as a whole across the seasons. Erisman — Asked what percentage of bluff face is represented by the homeowners who has his own erosion mitigation structure. Hartnett — Per the permit, we can't include those properties. Gasbarro — That property is about 130-140 of the 950 feet It might not have been as successful as it is if not for the stability of the bluff behind it. Bennett — The bathymetric surveys are mostly being done right in front of the tubes. Since sand comes off here and moves, it might help to know if that off -shore habitat farther down is being impacted. Hartnett — The monitored area is defined in the Order of Conditions. Golding — In regards to Ms Hartnett's response to how long the geotubes were exposed, he has photos showing the geotubes fully exposed on March 4 and they were not covered until March 18. He's puzzled about the claim that the independent reviewer supported the comment that SBPF is providing more sand than the surrounding bluff; the review's comments explains the erosion of the unprotected bluff and seems to contradict this claim. Also the claim that the geotubes were a 3 year project conditions on going forward with the expanded Notice of Intent (NOI). Department of Environmental Protection's (DEP) succeeding Order of Conditions makes clear that isn't the case; cites DEP approval dated December 9, 2014 which allows it as a temporary structure for six years with three years of the life of the permit and a request for an extension of an additional three years. In the peer review, it makes the point that as soon as the geotube is uncovered, it is acting as a Coastal Engineered Structure (CES). Roggeveen — Asked that the ConCom issue a report to the Select Board as to whether or not this stricture "is working". "Working" is a question is whether or not it is having an adverse impact up- and down -drift. Noted that the barrier beach in front of Sesachacha Pond is significantly less than it used to be, ergo the pond breached the dunes. You need to look at the dynamics over time. To Ms Erisman's point, the waves are hitting the sand in front of the tubes; it isn't reaching the bluff outside the project site. Should quantify the measurement in such a way to dissect that sand from other sand. Wegner — Part of the order of conditions states there is supposed to be a public beach in front of the tubes; if you look at only the low water mark, it won't show there is no beach at high tide. Page 2of3 Minutes for March 28 2018 adopted Apr. 11 Page 3 of 3 Hartnett — Noted that the Annual Report does address the beach at high tide. Molden — Applied Coastal has been reviewing erosion projects on Nantucket since the 1990s and asked him to review this report to advise NCL. Ruthven — Referenced his letter of review prepared for NCL: instead of the mean high or mean low, should be looking at the mid -tide level; explained why the amount of sacrificial sand should not be reduced. Erisman — During the March 26 site visit, the tubes were not completely covered. Asked if they are now covered; if not, when. Feeley — They have them partially covered but are still working on that. The front is still not completely covered. Golding — Confirmed that they started delivering material March 13 with significant deliveries by March 14 on the south end and there was no ramp at Hoicks Hollow. He can provide supporting photos for the commission. Feeley —The Storm Report will have all the information about the timeline of sand deliveries. Atherton — She compared the annual report to the original Order of Conditions, which has 52 special conditions. There are 900 linear feet of beach habitat has been destroyed. In terms of special conditions, where is the monitoring of the walkable beach, how many tide cycles or days have the geo-tubes been exposed, and a condition says that the monitoring program will not be changed under this order but the quarterly report no longer has the interpretive statement from an independent reviewer. The whole purpose of the project was to provide time for the Town to secure alternative access to the threatened section of Baxter Road; we have never seen that progress report. NCC wants to know the ConCom's response to their questions; thanked SBPF for answering them. Cohen — A lot of points were raised on monitoring methodology. The next annual report will cover the 2018 storm season. Erisman — Asked when ConCom would review the storm report. (Golding concurred) Carson — The storm report will be included on an April agenda for discussion. Motion Motion to Accept the Annual Report into the record. (made by: Champoux) (seconded by: Topham) Vote Carried 5-0 voice vote: Golding -aye, Erisman-aye, Bennett -aye, Champoux-aye, Topham -aye C. Other Business 1. None Motion to Adjourn: 6:35 p.m. Submitted by: Terry L. Norton Page 3 of 3 •l fit W— Vg z