Summer 2019 Seawall Reconstruction Presentation
2019 NVC Annual Meeting Article No. 7 • Seawall repair/replacement. To see if the Northport Village Corporation will vote to authorize a majority of the Overseers of the Corporation to borrow on behalf of the Northport Village Corporation a principal amount not to exceed $1,600,000, and to issue and sell general obligation bonds or notes of the Northport Village Corporation for that purpose to fund the repair / replacement of the seawalls extending from the boat ramp to the far side of the yacht club which protect the shoreline, causeway, and sewer treatment building and related site work. Such bonds and notes to be issued upon such further terms or conditions as may be determined by a majority of the Overseers of the Northport Village Corporation, and further to authorize the overseers to accept and expend federal or state grants, execute any and all contracts and documents and take any and all actions necessary or convenient to issue the bonds or notes of the Northport Village Corporation and accomplish the Project. of the Northport
Seawall Discussions Prior to 2019….. • Discussion going on for 10+ years • Previous design more than 5 years ago by wharf designer was rejected as not considering all options • 2016 inspection report….”useable but decaying condition”…”hesitant” to provide a life expectancy because of storm potential • 2016 report introduced options A-H 2016 report in
2016 Options A-H, plus “I” - Hybrid • Looked at Option A – “Do nothing” • Eventually crib will disintegrate and erode to an approximate slope of 4-6:1. Even at 6:1 it will not be stable and subject to future erosion issues. At 6:1 the erosion will eat into about 50 feet into the park and inhibit access to the causeway, if it is not destroyed as well. • Option A – not recommended • Options B, D, E, F, G, H, & I – carried forward
Design Team – Multiple Specialists • Milone and MacBroom • Landmark Corporation Surveyors & Engineers • Pinnacle Engineering • Prock Marine Prock Marine
Design – Comparison of Relative Costs
Design – Comparison of Relative Costs
Design – Comparison of Relative Costs
Recommended Alternative in 2018
NVC 2018 Annual and Subsequent Meetings • Some prefer a vertical wall option even if it will cost more • Carried two designs to 50% in 2019
2019 Seawall 50% design • Looked at “revetment” and “seawall” options • Considered capital costs, life expectancy • Examined how it would fit into the existing Infrastructure • Developed Article of Annual Meeting Annual Meetin
Background Terms • Define “Seawall” • Define “Revetment” • Define “Long-Lasting” • Define “Site Design”
Background Terms • Define “Seawall” • Define “Revetment” • Define “Long-Lasting” • Define “Site Design”
Seawall in Ruggles Park • Often think of seawall as the vertical wooden wall(s) by ramp • In reality, A seawall is anything that is used to “wall-off” the land from the sea
Background Terms • Define “Seawall” • Define “Revetment” • Define “Long-Lasting” • Define “Site Design”
Background Terms • Define “Seawall” • Define “Revetment” • Define “Long-Lasting” • Define “Site Design”
Revetment Definition • re·vet·ment (n) a retaining wall or facing of masonry or other material, supporting or protecting a rampart, wall, etc. • All “seawalls” are “revetment”
Background Terms • Define “Seawall” • Define “Revetment” • Define “Long-Lasting” • Define “Site Design”
Background Terms • Define “Seawall” • Define “Revetment” • Define “Long-Lasting” • Define “Site Design”
“Long-Lasting” Definition • Wood walls 25+ years • Granite walls w/ pins 50+ years • Rip-rap 50+ years • Maintenance different on each
Background Terms • Define “Seawall” • Define “Revetment” • Define “Long-Lasting” • Define “Site Design”
Background Terms • Define “Seawall” • Define “Revetment” • Define “Long-Lasting” • Define “Site Design”
“Site Design” Work • The circle will needed to be rebuilt • Wooden wall is actually a crib and buried into the hill • The vertical boards are nailed into the crib • At least half of the circle will be torn up to remove the old cribbing buried behind the vertical boards
“Site Design” Work • Approximate minimum limits of site staging area/reconstruction area
“Site Design” Work • The Selected Pre- Design – Option 3 from last summer includes: • Parking, • Sitting area, & • Accommodates either the vertical or sloped wall sloped wall
“Site Design” Work • Pre-design did not include any significant grading yet • Therefore, no additional consideration for land based runoff erosion
“Site Design” Work • Currently no storm drains in the staging area, none below circle
“Site Design” Work • Runoff overflows current wall, boat ramp, northern kneewall, and rip-rap
“Site Design” Work • Current, Existing Conditions
“Site Design” Work • Future, Sloped Revetment Conditions
“Site Design” Work • Future, Vertical Revetment Conditions
Vertical Wall Design Plan, Elevation & Cross Section • Plan
Vertical Wall Design Plan, Elevation & Cross Section • Plan
Vertical Wall Design Plan & Cross Sections • Plan
Sloping Wall Design Plan & Cross Sections • Plan
Sloping Wall Design Plan & Cross Sections • Plan
Final Design Details Remaining • Design at 50% • Conditions still TBD in final design are “circled” in grey • The arrow points to Pandora’s Box
Extent of Work • How does the new wall fit into the existing causeway “Wall”?
Extent of Work • How does the new wall fit into the existing causeway “Wall”?
Extent of Work • Looks like granite wall from the top • Eroding and collapsing • No way to tie in new wall
Extent of Work • How does the new wall fit into the existing causeway “Wall”?
Extent of Work • How does the Southside of the causeway compare to the north? • Even more bowed and problematic • More rock settlement settlement
Extent of Work • How does the Southside of the causeway compare to the north? • Even more bowed and problematic
Extent of Work • How does the Southside of the causeway compare to the north? • Even more bowed and problematic
Extent of Work • How does the Southside of the causeway compare to the north? • Even more bowed and problematic
Extent of Work • How does the Southside of the causeway compare to the north? • Even more bowed and problematic
Extent of Work • How does the Southside of the causeway compare to the north? • Even more bowed and problematic
Extent of Work • How does the Southside of the causeway compare to the north? • Even more bowed and problematic
Extent of Work –Piling Option? • Driven in to hold back land
Extent of Work – What do we want? • How does the Southside of the causeway compare to the north? • Even more bowed and problematic
Extent of Work – What do we want? • How does the Southside of the causeway compare to the north? • Even more bowed and problematic
Extent of Work – What do we want? • How does the Southside of the causeway compare to the north? • Even more bowed and problematic
Extent of Work – What do we want? • How does the Southside of the causeway compare to the north? • Even more bowed and problematic
Extent of Work – What do we want? • How does the Southside of the causeway compare to the north? • Even more bowed and problematic
Alternatives Considered and Potential Costs • How does the Southside of the causeway compare to the north? • Even more bowed and problematic
2019 NVC Annual Meeting Article No. 7 • Seawall repair/replacement. To see if the Northport Village Corporation will vote to authorize a majority of the Overseers of the Corporation to borrow on behalf of the Northport Village Corporation a principal amount not to exceed $1,600,000, and to issue and sell general obligation bonds or notes of the Northport Village Corporation for that purpose to fund the repair / replacement of the seawalls extending from the boat ramp to the far side of the yacht club which protect the shoreline, causeway, and sewer treatment building and related site work. Such bonds and notes to be issued upon such further terms or conditions as may be determined by a majority of the Overseers of the Northport Village Corporation, and further to authorize the overseers to accept and expend federal or state grants, execute any and all contracts and documents and take any and all actions necessary or convenient to issue the bonds or notes of the Northport Village Corporation and accomplish the Project. of the Northport
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