Comprehensive Storm Drainage Improvement Study For the Village of Amityville Town of Babylon, Suffolk County, New York
Prepared for; Prepared By
Village of Amityville Nelson & Pope Department of Public Works 572 Walt Whitman Road 21 Ireland Place Melville, NY 11747-2188 Amityville, NY 11701 June 2018
COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
TABLE OF CONTENTS
EXECUTIVE SUMMARY 1 1.0 INTRODUCTION 4 1.1 Background 4 1.2 Study Purpose 6 1.3 Study Area 7 1.4 Land Use and Population 9 2.0 FLOOD HISTORY, FEMA MAPS AND FLOOD RISK 12 2.1 Flood History 12 2.2 FEMA Flood Maps 16 3.0 GOALS, OBJECTIVES AND OPPORTUNITIES 18 3.1 Study Goal 18 3.2 Study Objectives 18 3.3 Study Opportunities 19 4.0 STUDY IMPLEMENTATION 20 4.1 Data Collection and Preparation of Plans 20 4.2 Field Visits and Observed Flooding 21 4.3 Existing Conditions 22 4.4 Analysis of the Existing Drainage Systems 25 5.0 MODELING AND HYDRAULIC ANALYSIS 28 6.0 POTENTIAL ALTERNATIVES 30 6.1 Potential Environmental Permits Required for Alternatives 30 6.2 Description of Various Strategies and Improvements 36 6.3 Proposed Improvements 38 7.0 IDENTIFIED PROBLEM AREAS, ASSOCIATED CONSTRUCTION 44 COSTS AND BENEFITS 7.1 Identified Problem Areas 44
Table of Contents COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
7.2 Associated Costs 48 7.3 Benefits 55 8.0 PROPOSED PROJECTS 57 8.1 Proposed Projects 57 8.2 Funding Sources 58 9.0 RECOMMENDED PROJECTS 61
FIGURES Figure 1 Map of Study Area 8 Figure 2 Land Use Map 10 Figure 3 Population Map 11 Figure 4 Sea, Lake and Overland Surges from Hurricanes (SLOSH) Map 15 Figure 5 NYSDEC Freshwater & Tidal Wetlands 35
APPENDICES Appendix 1 Master Drainage Plan Appendix 2 Elevation Map Appendix 3 Flood Insurance Rate Map and Hurricane Surge Zone Map Appendix 4 Tidal and Freshwater Wetlands Map Appendix 5 Improvement Details Appendix 6 Photo Log Appendix 7 Cost Basis for Alternatives Appendix 8 Resident Complaints Received by Village Appendix 9 Concept Plans
Table of Contents COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
EXECUTIVE SUMMARY
The Comprehensive Storm Drainage Improvement Study for the Village of Amityville has been prepared by Nelson & Pope, Melville, New York at the request of the Village of Amityville under the guidance of New York State Governor’s Office of Storm Recovery (GOSR). The project has been funded and conceived through the New York Rising Community Reconstruction Program of the Governor’s Office of Storm Recovery.
In 2012, Long Island’s south shore was besieged with stormwater due to Superstorm Sandy, like the 2011 storm, Hurricane Irene. Floodwaters inundated roadways, homes, schools, Municipal buildings, and businesses and made streets impassable and areas unusable. The storm surge from Superstorm Sandy pushed seawater into the Narraskatuck Creek, Amityville Creek and Woods Creek, overflowing the shoreline banks, canals, and bulkheads into the low-lying areas of land within the community. The devastation was substantial with more than 900 homes experiencing major damage, 23% of the entire housing units in the Village. The elevation of the study area south of Merrick Road varies between 2 to 10-feet above sea level. The areas along the Great South Bay shoreline and areas adjacent to the creeks and canals experienced damaging water from the peak storm surges during high tide that rose over the bulkheads and filled the drainage systems, backing up into adjacent neighborhoods. Many homes suffered significant damage from Superstorm Sandy’s storm surge and some remain vacant to this day. The Village of Amityville has been experiencing more frequent flooding events due to moon tides and/or high tides that have directly affected the quality of life throughout the community.
The Rising Community Reconstruction (NYRCR) Program established by the State of New York empowers the “most impacted communities with the technical expertise needed to develop thorough and implementable reconstruction plans to build physically, socially, and economically resilient and sustainable communities.” In 2014, a group of community residents and leaders from the Village of Amityville and the Hamlet of Copiague formed the Village of Amityville / Copiague NY Rising Community
Executive Summary
1 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
Reconstruction Planning Committee, which created a plan to rebuild the damage caused by Superstorm Sandy and to prepare for any future storms. In March 2014, NYRCR Program issued its report for the Village of Amityville / Copiague Community. The report contains sections that describe the community overview; provide an assessment of risks and needs; describe the reconstruction and resiliency strategies; and develop the proposed projects for implementation for Village of Amityville and the Hamlet of Copiague in the Town of Babylon.
The NYRCR Plan enabled Village of Amityville to be eligible for US Housing and Urban Development (HUD) Community Development Block Grant-Disaster Recovery (CDBG- DR) funding for long-term recovery and resiliency projects, with funding delivered through the NYRCR Program. The Village sought out qualified engineering firms through their Request for Proposal (RFP) process. In accordance with New York State General Municipal Law Section 104-b, the Request for Proposals (RFP) was designed to identify New York State licensed professional architectural and engineering (A/E) firms best qualified to provide the services necessary to prepare a comprehensive storm drainage improvement study followed by design, bidding and construction administration and inspection services for the NY Rising Community Reconstruction area of the Village of Amityville. The Village has retained Nelson & Pope, in coordination with sub-consultants Gayron de Bruin Land Surveying and Engineering, PC and CSM Engineering, to perform a comprehensive engineering inventory of stormwater collection, conveyance, and discharge components and to assess the Village of Amityville’s drainage systems, building upon the NYRCR Plans and Pre-application Reports. The engineering analysis will also evaluate the drainage system’s ability to accommodate storm flow and recommend improvements and solutions to satisfy these flooding conditions. The project will produce a strategy for drainage infrastructure upgrades pertaining to flood mitigation and when implemented, provide a more flood resilient community and will progress plans to the Final Design stage for those projects approved by the Village and through the construction of the approved projects.
The Drainage Report discusses the conditions of the existing drainage systems, the drainage outlets and bulkheads within the project area. Hydrological analyses of these drainage systems, how they were modeled, the assumptions and criteria used, and the
Executive Summary
2 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018 deficiencies identified are also included in this Report as well as a description of the various strategies and improvements to be considered; a comparison of these alternatives which shows the assessment of benefits, permits required, adverse impacts and the estimated construction cost of each alternative. The Report provides a list of proposed projects to address identified deficiencies within the Village of Amityville.
The Village will review the list of proposed projects from the report and then, in cooperation with the NYRCR Amityville Planning Committee and the Village of Amityville officials, will choose which projects will be progressed to Construction Contract Documents used I the Bid Process to obtain a qualified Contractor who will then construct the projects based on the allotted CDBG-DR funding.
Executive Summary
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1.0 INTRODUCTION
1.1 BACKGROUND
The Village of Amityville is in the southwest section of the Town of Babylon in Suffolk County, on Long Island, New York. The Village of Amityville is a suburban community dotted with residential neighborhoods. North of Merrick Road, the Village contains a variety of commercial uses and residential neighborhoods while the area south of Merrick Road is primarily residential with marine related businesses located on peninsulas separated by canals and creeks and the South Oyster Bay to the south. The Village residents value their connection to the water evident by the numerous homes located with their backyards on the canals, creeks, and the Bay. The Village of Amityville is comprised of 3.5 square miles with a population of 9,523 residents, based on the 2010 census.
There are three bodies of water that flow into South Oyster Bay; Narraskatuck Creek, Amityville Creek and Woods Creek. Residential homes are located along these creeks and along the numerous canals. There is one park in the Village, James Caples Memorial Park, located on the Bay that includes a small Village beach. Merrick Road is dotted with commercial businesses and the Business District or Downtown Amityville is located along Broadway (Route 110) and is the main commercial and civic areas within the community
Starting in August 2011, Long Island experienced several extreme weather events. Including Hurricane Irene, Tropical Storm Lee and Superstorm Sandy, that wreaked havoc on Long Islanders and their communities. These events signaled that Long Islanders must now deal with the reality defined by rising sea levels and extreme weather events that will occur with increased frequency and power. They also signaled that Long Islanders need to rebuild their communities in a way that will mitigate against future risks and build increased resilience.
Hurricane Irene struck on August 26, 2011, causing significant flooding, wind damage, and power outages. In early September, Tropical Storm Lee struck New York. Although the major damage brought on by Tropical Storm Lee was to up- state New York, Long Island received heavy rains which brought flooding to many communities.
Introduction
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In 2012, life changed dramatically for many community residents and business owners. New York and the tri-state area were devastated by Superstorm Sandy, the largest storm of the 2012 Atlantic Ocean hurricane season. The severity of Superstorm Sandy was a combination of factors; the storm’s arrival coincided with a “spring” tide (a high tide that occurs during a full moon) and the storm was just enormous, approximately 1,000 miles in diameter, which contributed to an elevated storm surge.
The powerful storm pushed water from the Atlantic Ocean directly onto Long Island. The stormwater drainage systems were overmatched by the surging tides and poured water into streets. The south shore of Long Island, including the Village of Amityville, suffered massive storm damage, power outages, and utility and transportation disruption. Most of the homes south of Merrick Road were inundated with up to four feet of water. Boats and debris battered bulkheads, docks and other structures and were tossed onto land, further damaging homes and property along the Bay and the canals. Evacuation and emergency response was severely hindered or impossible as a result of flooding, even after the brunt of the storms. Directly or indirectly, the lives and well-being of virtually everyone in the region were and continue to be affected by the aftermath of these storms.
Superstorm Sandy severely damaged the Village of Amityville’s stormwater drainage systems. Since then, the Village has experienced reoccurring and frequent flooding during moon tides and/or high tides due mainly to instances of tidal backflow through the stormwater drainage systems. The tidal surges from these events is frequently and causes recurring flooding which rises over bulkheads and backs up through the drainage systems from a combination of average rain fall, high tides, and nor’easters, inundating local roadways and residences. These events are a burden to the municipality in terms of costs for repair/maintenance, emergency services by the necessary reaction to the events and affects other services including but not limited to the disruption in sanitary curbside garbage collection, interruption of mail services, and school bus route changes. There is also the threat of safety especially to the elderly and handicapped population of the area who may need access to doctors, hospitals and pharmacies. The tidal flooding
Introduction
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in roadways also damages property including vehicles parked and/or driven through the salt water.
1.2 STUDY PURPOSE
In response to these damaging storms, the NY Rising Community Reconstruction (NYRCR) Program was established by the New York State (NYS) to provide rebuilding and revitalization assistance to communities severely damaged by Superstorm Sandy, Hurricane Irene, and Tropical Storm Lee. As noted previously, this program empowers communities to identify resilient and innovative reconstruction projects that consider current damage, future threats, and economic opportunities—all of which are contained in the NYRCR Village of Amityville/Copiague Plan.
Residents, business owners, first responders, and local employees from the Village actively participated in the NYRCR Program over a period of several months resulting in the March 2014 NYRCR Village of Amityville/Copiague Plan. These stakeholders considered their goals and aspirations for the future to develop an NYRCR Plan that honors the unique qualities and assets of these communities, that seeks to creatively reduce potential storm and climate change related impacts, and that leverages these investments to support other needs and opportunities that can ultimately benefit the Village of Amityville and Copiague as a whole. The result of these efforts are included in this NYRCR Plan and presents a series of strategies and projects that respond to critical issues, and contribute to building a more resilient, safer, and sustainable future for the Village of Amityville and Copiague.
The geographic scope of the NYRCR Plans includes the entirety of the Village of Amityville and the Hamlet of Copiague and has been allocated a total of $14.2 million for both communities. GOSR has indicated that $5.6 million of this allocation has been set aside for the design, permitting, construction and inspection/management of the various projects as outlined in the Village of Amityville/Copiague NYRCR Plan.
One of the strategies/projects that arose from the NYRCR Plan is this Village of Amityville Comprehensive Storm Drainage Improvement Study. Of the $5.6 million allocation for the Village of Amityville, approximately $1.68M is to be used for construction of the selected project as recommended in this Comprehensive Storm Drainage Improvement Study. The Drainage Improvement Study will assess the existing stormwater drainage systems; analyze these systems and identify deficiencies; develop various strategies and improvements; compare these
Introduction
6 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
alternatives assessing benefits, required permits, adverse impacts, and construction costs; make recommendations based on priority areas/needs. In addition to the report, N&P will develop Construction Plans and will oversee the construction of the chosen recommended projects outlined in this Drainage Report.
1.3 STUDY AREA The focus area is comprised of the Village of Amityville, in Suffolk County on Long Island, New York.
Introduction
7 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
Figure 1 – Map of the Study Area in Suffolk County
Introduction
8 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
1.4 LAND USE AND POPULATION
Based on the “2010-2014 American Community Survey - 5 Year Estimate”, the population of the Village of Amityville is 9,523 with an average age of 45.2. The Village of Amityville is predominantly residential, single family homes with some commercial properties. There are approximately 1735 companies in the Village.
More than 21% of the households in the Village of Amityville have children under the age of 18 living with them, while approximately 36% of the population is over 55 years old. (See Figures 2 and 3 below).
Introduction
9 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
Figure 2 Land Use Map of the Village of Amityville
Introduction
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Figure 3 Population Map of the Village of Amityville
Introduction
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2.0 FLOOD HISTORY, FEMA MAPS AND FLOOD RISK
2.1 FLOOD HISTORY
For decades on Long Island, flooding has been a concern especially for communities along the south shore like the Village of Amityville. Long Island is subject to coastal flooding caused by Nor’easters and hurricanes. Nor’easters can occur at any time of the year, but are more prevalent in the winter, whereas hurricanes occur in the late summer and early fall. Hurricanes are of shorter duration than northeasters and generally last through only one tidal cycle. During a hurricane, low pressure and high winds combine to produce abnormally high tides and accompanying tidal flooding. In 1960s and 1970s, Long Island experienced two (2) major hurricanes, Hurricane Donna (September 1960) and Hurricane Belle (August 1976).
Although Superstorm Sandy was the most destructive storm to make landfall on Long Island in recent history, Hurricane Irene caused significant damage only 14 months prior. Residents living in areas at 10 feet above sea level and below were issued an evacuation order by the County prior to Hurricane Irene making landfall. On August 28, 2011 Hurricane Irene made landfall as a Category 1 hurricane, quickly weakening to a tropical storm. Heavy rain and storm surge caused extensive flooding. It is estimated that the surge raised the Atlantic Ocean by eight feet as it swept into Long Island during high tide, sending saltwater spilling into communities. Many local streets were impassable by car. High winds felled trees, compromised power lines and led to widespread power outages. The total cost for preparation, clean up, and damage repair in Suffolk County was in the millions of dollars.
Fourteen months later, on October 29, 2012, Superstorm Sandy devastated New York and the Tri-State region. The communities along the south shore of Long Island suffered massive storm damage, power outages, and utility and transportation disruption, primarily as the result of wind and storm surge, rather than the heavy rain that was experienced during Hurricane Irene. A storm surge occurs when an abnormal rise of water is generated by a storm over and above the predicted astronomical tide. Berger Ave/ Shore Rd, Amityville
Flood History
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Flooding from the storm reached and surpassed the Federal Emergency Management Agency’s (FEMA) 100-year flood zones on Long Island. A 100-year flood zone is a statistical way of expressing an area that has the potential of being flooded one in one hundred or 1% chance of happening in any given year. According to the National Weather Service, the maximum storm surge in the Community was approximately eight feet at 9:00 p.m. on October 29, which coincided with the high tide. The total water level reached approximately 11 feet above mean sea level. The storm surge was exceptional because of both the speed and motion of the storm, as well as the storm’s arrival at high tide which pushed seawater through South Oyster Bay into Narraskatuck Creek, Amityville Creek and Woods Creek. Large swaths of land were flooded, and the Village faced severe problems with power outages, heavy debris, and difficult travel conditions due to damaged and flooded roads and compromised power lines.
Flood History
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In all, more than 900 housing units were flooded with 23% of the homes in the Village sustaining damage, many seeing as much as 4 feet of water. The waterfront housing took the biggest hit. The Amityville Beach Pavilion experienced six feet of storm surge damaging the facility’s electrical, plumbing and fence. Superstorm Sandy’s impact extended well beyond the area’s homeowners. Superstorm Sandy also exposed the vulnerability of the commercial center to the storm surge. Many of business establishments, which flooded during Superstorm Sandy were unable to reopen for several months. Evacuation during the storm and delivery of supplies after the storm was difficult in certain neighborhoods. Superstorm Sandy made evident the issues for emergency management with lack of fuel, power, and communications
Much of the Village’s drainage infrastructure was damaged including drainage structures, pipes and outfalls as a result of effects of Superstorm Sandy. The volume of water and debris associated with the storm overwhelmed and severely impacted the drainage system. Catch basins were silted in and damaged; pipes fractured, causing water to undermine bulkheads instead of draining into outfalls. Some of these drainage systems are no longer able to efficiently drain the roadways and adjacent properties during regular rainfall events or prevent the canals and bay from back-flowing through the system during high tides. Currently, significant areas experience localized flooding because of these inadequacies especially in the low elevation of the community south of Merrick Road. Homes and vehicles suffer damage and critical access for residents, businesses and emergency services is compromised.
Most of the study area south of Merrick Road is in low lying areas with elevations ranging from elevation 2 to elevation 10 (NAV 88). Hurricanes are classified into four (4) categories which coincide with the severity of the hurricane, Category 4 being the strongest and most severe. Figure 4 shows the effect of the four categories of a hurricane on the study area. A Category 1 hurricane inundates just about all of the immediate south shore of Long Island and specifically the lower third of the two peninsulas on the southern tip of the Village. A Category 2 hurricane inundates just about all of the immediate south of Merrick Road making it nearly impassable.
Category 2 would inundate both peninsulas up to Merrick Road. Flood waters would approach the Long Island Railroad and the Amityville Downtown during a Category 3 hurricane. A Category 4 hurricane would pass the Long Island Railroad inundate the southern half of the Village and making travel of Sunrise Highway difficult.
Flood History
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Figure 4 – Sea, Lake, and Overland Surges from Hurricanes (SLOSH) Map
Flood History
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2.2 FEMA FLOOD MAPS The primary source for floodplain or flood prone area information is the Federal Emergency Management Agency (FEMA). FEMA publishes Flood Insurance Rate Maps (FIRMs) and Flood Insurance Studies (FIS) that are used by local entities for floodplain management purposes. The 1% annual chance (100 year) flood has been adopted by FEMA as the base flood for flood plain management and flood insurance purposes and the elevation associated with the 100-year storm provides the Base Flood Elevation (BFE). A 1% annual chance flood (or base flood) has a 1 in 100 annual chance of being equaled or exceeded in any given year. FEMA also uses the 2% annual chance (500 year) flood in determination of less severe flood zones.
According to FEMA’s Flood Insurance Rate Maps (FIRMs), sections of the Village of Amityville fall within the areas designated as Zone AE and Zone X (see Appendix-3 for FEMA Flood Map). Advisory Zone ‘AE’ is the area subject to storm surge flooding from the 1% annual chance (100-year storm) coastal flooding but are not subject to high velocity wave action. In the ‘A’ Zone, the water rises and recedes, but it lacks the damaging wave action. Advisory Zone X is a non-special flood hazard area and has a 2% annual chance of flooding (500 year flood) or a 1% chance of experiencing flooding of less than 1 foot any given year. The FIRM also provides the Base Flood Elevation or BFE. For the Village of Amityville, the BFE ranges between 6 and 7 feet based on North American Vertical Datum of 1988 (NAVD 88).
FEMA defines the Base Flood Elevation (BFE) as the elevation to which floodwater is anticipated to rise during the base flood or the 1% annual chance (100 year) flood. In September 2014, Governor Cuomo signed the Community Risk and Resiliency Act (CRRA) which implemented guidance on mitigation of sea-level rise (SLR) based on funding source. A provision of the CRRA drafted by the Department of Environmental Conservation (DEC), 6 NYCRR Part 490 made projections for global sea-level rise based on the 2000 to 2004 baseline sea-level rise. For Long Island, the projections are:
6 NYCRR Part 490 Projected Sea-Level Rise (inches) Long Island Year Low Low- Medium High- High Medium Medium 2020 2 4 6 8 10 2050 8 11 16 21 30 2080 13 18 29 39 58 2100 15 21 34 47 72
Although these projections have been established by NYSDEC for Long Island, New York City/Lower Hudson, and Mid-Hudson, the NYSDEC has not imposed
Flood History
16 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018 new standards or criteria for permitting or funding eligibility but has intended these projections to be used in analyses of climate change impacts.
Typically, and especially when dealing with the construction/reconstruction of bulkheads, the guidance is to raise to the Base Flood Elevation plus 2 feet. Considering the elevation of Amityville south of Merrick Road to be as low as elevation 2 or 3, the Base Flood Elevation is between 6 and 7 feet, and the sea-level rise ranges from 6 inches to 34 inches (for medium sea-level rise), constructing/reconstructing bulkheads could require a change of elevation form 6 feet 6 inches to 8 feet 10 inches. Following the typical guidance of BFE plus 2 feet and these new projections to build to, raising bulkheads or roadways could be dramatic and are unrealistic.
Flood History
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3.0 GOAL, OBJECTIVES AND OPPORTUNITIES
3.1 STUDY GOAL
This Comprehensive Storm Drainage Improvement Study will identify a targeted or phased approach to upgrades based on its outcome. This effort would allow the Village communities to identify “hot spots” prone to flooding as well as to obtain a complete view of the state of their infrastructure. Moving forward, this Drainage Study will function as the basis for future drainage infrastructure improvements.
The goal of this Drainage Study is to identify and provide adequate flood damage reduction measures that are technically feasible and financially prudent to ensure the safety of the study area of the Village of Amityville without increased flood damages in neighboring communities and affecting community infrastructures.
While the projects identified in the Drainage Study would not eliminate all flood risks, especially those associated with a major natural disaster or storm event like Superstorm Sandy; however, it would reduce risk, especially for moderate to low level storm events.
3.2 STUDY OBJECTIVES
This study has been based on the strategies in the NYRCRP for the Village of Amityville / Copiague. This study will look at the strategies of increasing conveyance capacity, reconstruction/replacement of outfalls, installation of check valves, replacement and/or adding additional inlet structures (catch basins), raising roadways, and green infrastructure measures which reduce runoff and/or contaminant loads in run off. The Request for Proposal (RFP) for this study identified the following tasks for the Village storm drainage system south of the LIRR:
• An engineering inventory and inspection of the drainage infrastructure,
including elevations, • Identification location in need of improvement through an engineering analysis of the system needs, including the determination of the ability of the drainage system to accommodate storm flow; • Identification of a series of conceptual designs to address identified localized and system-wide deficiencies/issues including costs; • The identification of areas or issues of concern and prioritization of repairs/improvements; and
Goal, Objectives & Opportunities
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• Selected projects outlined in the Drainage Report will be progressed and developed into 100% Final Contract Document and Construction Cost Estimates.
3.3 STUDY OPPORTUNITIES
The following potential opportunities were identified while studying the area and will be evaluated for the implementation of the alternatives discussed:
• Creation of stormwater treatment systems that are depressions integrated into the landscape or bioretention areas to detain and treat road runoff.
• Inclusion of stormwater treatment structures to segregate stormwater from debris and oils carried by the road runoff.
• Identification of Town/Village owned properties that could potentially be used for a stormwater retention area, either a retention basin or a leaching field
• Identification of State/Town/Village owned areas with no existing bulkhead and the potential of constructing a living wall to both protect the Village property from erosion and clean/filter stormwater runoff prior to re- infiltration into the ground.
Goal, Objectives & Opportunities
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4.0 STUDY IMPLEMENTATION
4.1 DATA COLLECTION AND PREPARATION OF PLANS
N&P reached out to the Village to obtain drainage records for any and all existing drainage systems, outfalls and bulkheads within the study area. After receiving this information, the information was plotted onto aerial CADD drawings in a logical order which provided information for a master drainage plan and smaller usable drawings for field editing and viewing (See Appendix 1 for Master Drainage Plan). Once plotted, the systems were checked by viewing aerials and performing field visits to verify, obtain, and locate all drainage structures throughout the entire Village.
The investigation proceeded with an advanced field inventory of each drainage structure, bulkhead and outfall south of Merrick Road which included inventory sheets of the existing conditions for each basin, pipe, bulkhead and outfall and information on the size, material, invert and rim elevation and any visual damage. With the aid of a handheld high accuracy Global Positioning System (GPS) surveying equipment, N&P recorded the latitude, longitude, rim/invert elevation and top of bulkhead elevation. The inventory information and the GPS information were then tabulated and compiled into spreadsheets and input into GPS. Approximately 336 structures were inventoried; many of the structures are missing information for various reasons including filled with debris and/or water; chimney depth and/or the orientation of the structure block view of the interior of the structure; the structure was buried underground, covered with asphalt or located under a parked car; the structure was located in the center of a high traffic roadway; or the structure was unable to be opened. Approximately 7% required cleaning, no drainage structures have filter inserts and no structures had check valves in them. Approximately 50 outfalls were inventoried, of which no outfall had a check valve on them.
Contours, taken from the New York State Geographic Information System (NYS GIS) LiDAR (Light Detection and Ranging), were added to the plan sheets and individual tributary areas were established to allow examination of each separate drainage system (see Appendix 2 for the Elevation Map). N&P visited the study area several times during differing storm events, minor storms and major storms including a Nor’easter and at times with and without tidal action. N&P visited the
Study Implementation
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known problem areas such as Riverside Ave, Mac Donald Ave, Shore Drive West, Norman Ave, Bay Ave, Unqua Place, Richmond Ave, Mincner Place, Dewey Ave, and Grand Central Ave, and identified other problem areas during these field visits (see Appendix 6 for Photo Log). During several visits, staff spoke to residents that emphasized the extent of flooding occurring in the community.
4.2 FIELD VISITS AND OBSERVED FLOODING During the study, N&P made numerous field visits during rain events including typical rain events, high tide with and without rain, and during major events (nor’easters). The dates of the field visits are as following with a description of the field visit and pictures of what was observed:
SITE VISITS Date Time High Tide Moon Phase Precipitation 2/25/2018 3 to 5 pm 6:05 pm 1st Quarter 0.76 in 3/2/2018 8 to 12 noon 10:13 am Full Moon 2.41 in 3/5/2018 8 to 12 noon 12:36 pm Full Moon 0.00 in 3/16/2018 11am to 3 pm 10:22 am New Moon 0.00 in 3/26/2018 12 noon to 3 pm 6:05 am 1st Quarter 0.00 in 4/12/2018 12 noon to 3 pm 8:20 am Waning Crescent 0.00 in
February 25, 2018 was a typical rain event with 0.76 inches of rainfall two (2) days past the 1st Quarter Moon with a high tide at 6:05 pm. During N&P’s field visit, flooding was observed at low points in the roadways and in some areas the tide was seen overflowing the catch basins.
Ocean Ave and Cole Ave – Rain Mincher Place and Dewey Ave – Tidal water overflowing catch ponding at low points Rain ponding along curb line basin grate
On March 2, 2018 a Nor’easter struck Long Island with 2.41 inches of rainfall one day after a full moon. The pictures were taken during a moon high tide and tidal flooding in evident. Major flooding occurred at numerous locations including Riverside Ave, Griffing Ave, Mac Donald Ave, Grand Central Ave, Minhner Place, Dewey Ave, Anita Place, Bayside Ave, Bayside Place, and Richmond Ave.
Study Implementation
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Griffing Ave at Riverside Ave Cooper Ave at Riverside Ave MacDonald Ave At Grand Central
South Bayview Ave at MacDonald Mincher Place and Dewey Ave Dewey Ave
Anita Place and Bayside Ave Bayside Place Richmond Ave at Unqua Place
4.3 EXISTING CONDITIONS
Within the limits of the Village of Amityville, primarily south of Merrick Road, the roadway elevations are at or below elevation 10, NAVD 88; with areas as low as elevation 3 that experience flooding associated with frequent storm events and high tides. The study area is has a level gradient with lower elevations adjacent to
Study Implementation
22 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018 the creeks and the bay and slowly increasing in elevation as you move north to Merrick Road.
The study area south of Merrick Road is primarily residential with some businesses mixed in; mainly marine based companies and eateries. Along Merrick Road, the businesses vary in type and size. North of Merrick Road up to the LIRR, the area is still mostly residential; however, along Broadway (State Route 110) the area is considered to be Downtown Amityville with numerous businesses and municipal buildings. Pockets of retail businesses found along Railroad Ave and adjacent street to the LIRR tracks. Park Avenue Memorial Elementary School and Amityville High School is located within the study area with several parks located around the study area as well, most notably James Caples Memorial Park and Amityville Municipal Bathing Beach Park which area both adjacent to the bay.
The existing drainage systems within the study area are both positive systems (a system of catch basins and manholes connected with pipe that carries road runoff off the roadway and discharges into streams, canals or directly into the bay) and leaching systems (a system of catch basins with porous walls that allows for road runoff to percolate into the surrounding ground). The majority of the positive systems discharge into drainage swales, creeks or canals that lead to the South Oyster Bay. These drainage systems date back to the 1950’s and 1960’s with specific systems being replaced and/or upgraded as recently as 2018.
The construction of the basins and manholes ranges from older brick and block structures to newer precast concrete structures. Most are typical Suffolk County designs for basins and manhole structures. The pipes are mostly reinforced concrete (RCP) or plastic pipes; however, more there are some older pipes made of corrugated metal and cast iron. The existing bulkheads are primarily timber structures with a small number of upgraded bulkheads made out of vinyl.
An inspection of the existing system was completed in the Spring of 2018 which identified basin/manhole size, type, elevation and condition; pipe direction, size, invert elevation and material; bulkhead/outfall size, type, material, invert elevation and top of bulkhead elevation. The majority of the basins and manholes were in fair to good condition. Some were filled with debris and/or water. Several pipes were showing signs of serious deterioration. The older timber bulkheads range from fair to critical, while the newer vinyl bulkheads appear in good to excellent condition. Several areas adjacent to the bulkheads have signs of washouts where the existing ground has sunk due to stormwater returning to the
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23 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018 canals through the bulkhead due to silting up or damage of drainage structures and/or fractured drainage pipes.
There was no evidence of any stormwater treatment structures existing within the study area; however, several catch basins did have filter bags to assist in removal of debris from stormwater runoff. Many of these catch basin filter bags have been removed during maintenance activities due to damage or constant clogging. Several catch basin filter bags have become so full of debris that road runoff cannot enter the existing drainage system. This Drainage structure with filter bag was evident on several roadways in the study area.
The existing drainage basin and manhole condition ratings were as follows:
• Approximately 0% Excellent • Approximately 71% good • Approximately 10% Fair • Approximately 5% poor • Approximately 3% failing • Approximately 11% undetermined
At the time of this Report, the Village has a bulkhead reconstruction project underway, the ‘Amityville Waterfront Resiliency Improvements Project’. This contract includes the reconstruction of the bulkhead with vinyl sheeting, replacement of the outfall, and inclusion of an inline check valve. Since this project is addressing most of the critical areas requiring bulkhead upgrades, this Report will only identify any remaining bulkhead upgrades, if any.
Approximately 60 outfalls (culvert headwalls, headwalls, pipe ends and pipes exiting through bulkheads) were inventoried of which majority of these outfalls had no visible existing check valves.
Bulkheading can protect properties from erosion and give some measure of protection from tidal flooding as seen along the many canals and creeks; however, the existing bulkheads along the community’s coast, canals and rivers vary in
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height, condition, material, and age. During the March 2, 2018 Nor’easter, some bulkheads were noticed to be overtopped by the high tidal waters.
4.4 ANALYSIS OF THE EXISTING DRAINAGE SYSTEMS
Specified known trouble areas and/or field observed areas with issues were analyzed using Autodesk Storm and Sanitary Analysis which is a AutoCAD based program. This program is a comprehensive hydrology and hydraulic analysis application commonly used for the planning and designing of stormwater drainage systems. The program analysis is ideal for medium to large positive systems that are in question as to how efficient it should be performing. Throughout the Village of Amityville, the existing systems range from standalone leaching units, to medium size positive systems; majority of which fall within the small positive system size (1 to 6 structures piped to an outfall).
Two locations that are known problem areas were chosen to be analyzed to determine the capacity and functionality of the existing pipes and structures in that system. These two locations fall along Richmond Ave at Mole Place and Bayside Ave. The initial step was to utilize LiDAR topographic information to determine a watershed for the area being analyzed. Next, the system information such as, structure size, type and rim elevation; pipe size, slope and invert elevation were input into the program. Once the system was input, it was analyzed for the year storm chosen.
The software program has the capabilities of adding tidal influence on the drainage system being analyzed. In addition, check valves can be used within the system to simulate this effect of preventing back flow of water into the drainage system due to tidal influence and to determine if the existing drainage system can handle the storm event while the check valve is closed; this being critical in most cases south of Merrick Road.
Autodesk Storm and Sanitary Analysis utilizes the Modified Soil Cover Complex Method based on Technical Release 55 (TR-55) to calculate peak discharge from watershed areas. TR-55 begins with a rainfall amount uniformly imposed on the watershed over a specified period of time. Mass rainfall is converted to mass runoff by use of a runoff curve number (CN). The curve number is based on soil parameters, vegetation, amount of impervious areas and interception. The runoff is then converted into a hydrograph by using unit hydrograph theory and routing procedures that depend on runoff travel time through segments of the watershed. A combination of 1yr, 2yr and 10yr storm events along with multiple field visits during rainfall events, were used to determine the most sensitive areas. The most prominent high tide rain events experienced during the project duration were on February 25, 2018 (rain event) and March 2, 2018 (Nor’easter). Each system was
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25 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018 modeled using a 10-year storm and the highest annual tide cycle from Sandy Hook (NAVD88).
Criteria used to analyze each outfall watershed area included: • The year storm (1yr, 2yr & 10yr storm events). • The rainfall (P), initial abstraction (Ia) and potential maximum retention after runoff begins (S). • Time of concentration (Tc). • The watershed areas (Am). • Rainfall distribution type (Suffolk County is a Type II over 24 hours). • Runoff coefficient. • Tidal Curve (Sandy Hook (NAVD88))
Assumptions made that affect the output of the analysis included:
• In order to analyze a system that extends outside the study area and leads to an outfall within the study area, the drainage pipe have been assumed to be flowing full.
• The watershed area was analyzed as a whole broken down into sub- watershed areas and the runoff coefficient was averaged for the various surface conditions within the watershed area.
• The Sandy Hook (NAVD88) tidal curve used is considered a worst-case scenario tidal/ storm surge condition which will account for current and future tidal conditions.
• All catch basins and manholes were deemed appropriate to have a one foot (1’) sump (sumps were inventoried on numerous structures; however, most sumps have been filled with debris).
• When drainage inventory was not able to be obtained from the field inventory, information was obtained from available record plans. If record plans were not available, engineering judgement based on minimal drainage design guidelines was used to determine critical design elements in order to complete the model.
The following deficiencies were inventoried and modeled:
▪ Tidal influence restricting discharge and in fact affectively using the positive drainage systems as a means for water to backflow onto the streets.
▪ Back pitched and excessively small diameter drainage pipes.
▪ Minor damage to the drainage system, not allowing the drainage system to function as designed.
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▪ Insufficient storm water capacity throughout systems.
▪ Roadway/inlet elevations that are situated at extremely low elevations.
▪ Drainage system designs based on the volume of storm water from the contributing areas of direct runoff.
▪ Lack of maintenance throughout the Village of Amityville due to insufficient resources and surrounding areas outside the Village that contribute to the Village of Amityville’s drainage systems.
▪ Failing bulkheads and/or discharge pipes leading to tidal flooding onto the streets or surrounding properties.
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5.0 MODELING AND HYDRAULIC ANALYSIS
After determining the most sensitive, high priority areas, models were developed to simulate the existing drainage system during specific storm events at specified locations. Each location modeled also has an existing history of consistent flooding, where flooding has been reported by the Village as well as residents of the Village of Amityville. Each of the systems analyzed were done so utilizing a 1 year, 2 year and 10-year storm over a 24- hour period (based on the Suffolk County Type II Rainfall distributed design storm). Each drainage system modeled is tidally influenced, and therefore an appropriate tidal curve was applied (tidal curve data used within the modeling depicts the highest annual tide cycle from Sandy Hook (NAVD88)). Each system modeled was analyzed to find exactly where the deficiencies exist, which can be seen through numerical data such as increased surcharge times, high discharge rate, and flooded drainage facilities including total flooded area and time flooded. The following deficiencies were results of either the model, field investigation and/or a combination of both analyses:
1. Tidal Influence restricting discharge at an outfall.
2. Tidal Influence causing a positive system to in fact work in the opposite fashion, becoming overloaded with rain water and discharging water onto the streets.
3. Insufficient storm water capacity in a positive system.
4. Insufficient pipe sizes throughout a positive system.
5. Roadway/inlet elevations situated at extremely low elevations, ultimately leading to a storage/ positive flow rate issue.
6. Damaged bulkhead/outfall locations, leading to poor discharge and tidal water infiltration onto residential streets.
7. Lack of Maintenance, leading to damaged and restricted storm water access through a drainage system.
8. Insufficient storage depths and outfall elevations due to low roadway/residential areas.
The most abundant flooding in the Village of Amityville can be found south of Merrick Road. Most of the existing drainage systems throughout this particular area are small positive systems found in concentrated areas flowing to an outfall discharge pipe.
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28 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
The following drainage systems were analyzed and are typical of the systems found in the Village:
• Bayside Place and Anita Place • Bayside Place and Richmond Ave • Richmond Ave and Mole Place • Richmond Ave and Hamilton Street • Riverside Street and Richmond Ave
This area surrounding Richmond Ave has a few medium sized positive systems with existing outfalls surround by small stand along systems that are not catching and/or storing the necessary volume of stormwater for these tributary areas. These local systems have been modeled to analyze how the current system would work if these small systems were to be connected to the existing positive system.
By connected these smaller positive drainage systems to the larger positive drainage system on Richmond Ave, the analysis identified major reconstruction of the entire drainage system due to the increase in volume of runoff from these new areas and the need to increase pipe sizes downstream. The cost of the reconstruction of the entire drainage system exceeds the benefits that would be obtained.
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6.0 POTENTIAL ALTERNATIVES
6.1 POTENTIAL ENVIRONMENTAL PERMITS REQUIRED FOR THE ALTERNATIVES
Several of the alternatives will require permits from a variety of agencies for the proposed drainage improvements that are located within wetland jurisdictional areas (see Appendix 4 for Wetland Maps), including the United Stated Army Corp of Engineers (USACE), New York State Department of State (NYSDOS), New York State Department of Environmental Conservation (NYSDEC) and the Town of Babylon (TOB).
United States Army Corps of Engineers USACE
The USACE regulates wetlands defined as “waters of the United States” through Section 401 of the Clean Water Act and Section 10 of the Rivers and Harbors Act. Generally, jurisdiction extends to the edge of the delineated vegetated wetland boundary or to the Spring High Water line. In an attempt to streamline processing for common activities, the USACE issued a set of 52 Nationwide Permits (NWP) for projects that fall under the thresholds of the permit category. An individual permit is required for proposed projects that occur within USACE jurisdiction and are not covered under any of the Nationwide Permits.
Generally, USACE Nationwide Permits can be applied to many of the proposed drainage improvements within the study area of the Village of Amityville. Projects for which coverage under a Nationwide Permit can be obtained include maintenance dredging to remove accumulated sediments from intake and outfall structures (NWP #3), repair, rehabilitation or replacement of an existing bulkhead (NWP #3), construction or modification of outfall structures and related intake structures (NWP #7). The installation of new bulkheads or other shoreline structures where no structure currently exists requires an Individual Permit.
Multiple improvements may be proposed within the study area which include in- kind and in-place bulkhead replacement, plugging of existing outfalls and the installation of check-valves into the remaining outfalls. The proposed bulkhead replacement would fall under Nationwide Permit #3 which covers “repair, rehabilitation, or replacement of any previously authorized, currently serviceable, structure.” Activities related to the construction or modification of outfall structures are covered under NWP #7, and as such pre-construction notification would be required prior to the proposed drainage improvements.
Any proposed bulkhead replacement would be covered under Nationwide Permit #3 which covers “repair, rehabilitation, or replacement of any previously authorized, currently serviceable, structure”. Activities related to the construction
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30 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018 a new outfall structure are covered under NWP #7, and as such pre-construction notification will be required prior to the addition of an outfall structure.
The addition of drainage facilities that occur outside of USACE jurisdiction would not require a USACE permit.
The USACE has specific requirements for application submission. In an effort to reduce the total number of application papers submitted the USACE, NYSDOS and NYSDEC have created a Joint Application for Permit form for wetland applications which must be submitted to all agencies. In addition to a completed Joint Application, applicants are required to submit a USACE Environmental Questionnaire, Essential Fish Habitat Worksheet (EFH), a project plan with cross- section view (8.5 X 11), photographs of the project location, location map, and copies Federal Consistency Form (FCAF) prepared for the New York Department of State Coastal Consistency Concurrence application.
New York State Department of State NYSDOS
The NYSDOS requires Coastal Consistency Concurrence for all projects in which an USACE permit is required. In some cases, general concurrence is issued for a particular Nationwide Permit while in other cases Individual Consistency Concurrence is required. Individual Consistency Concurrence is always required if an Individual Permit is required from the USACE.
The proposed plugging of outfalls and installation of check valves as well as the installation of an outfall will require individual Consistency Concurrence determinations from NYSDOS. Individual Consistency Concurrence will also need to be obtained for all activities related to outfall and intake structures covered under NWP #7. Proposed bulkhead improvements covered under USACE NWP #3 will receive general Consistency Concurrence and will not need individual determinations.
The NYSDOS requires Coastal Consistency Concurrence applications to include a copy of the Joint Application submitted to NYSDEC/USACE, and a Federal Coastal Assessment Form (FCAF) with a written discussion of applicable State Coastal Management Policies. NYSDOS also receives a copy of the project plan, photographs of the project location, aerial photographs and a location map.
New York State Department of Environmental Conservation NYSDEC
Article 25 The New York State Department of Environmental Conservation (NYSDEC) regulates tidal wetlands under Article 25 of the Environmental Conservation Law (ECL). NYSDEC regulated tidal wetlands are illustrated in Figure 6. Part 661, Tidal Wetlands Use Regulations, effective August 5, 1992, establishes the regulations for tidal wetlands including developmental restrictions, permit
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requirements, and existing land use and development. Jurisdictional limits for tidal wetlands are established in part 661 and generally include setbacks/distances of 300 feet from the wetland boundary (vegetated or the apparent high water mark), or the limit of the 10 foot elevation contour (NAVD 88), or the top of a slope or bluff unless there is a permanent shoreline structure that existed prior to August 20, 1977 and continues to function, or a road more than 100 feet in length.1 The NYSDEC has issued General Permit for Bulkhead Removal and Replacement (GP- 1-13-001) for projects located on the south shore of Long Island in areas west of Robert Moses Causeway, excluding areas of vegetated tidal wetlands, ocean shore, Long Beach Island oceanfront, Jones Beach State Park and Robert Moses State Park.
Generally, Article 25 Individual Permits will be required for select proposed drainage improvements within the study area of the Village of Amityville. Projects for which permits will be necessary include the closing of existing outfalls, the modification of existing outfalls to include new check-valves, replacement of existing outfall pipes, installation of new outfalls, construction of new bulkheads, maintenance dredging of canals and the removal of invasive Phragmites (Phragmites australis). The in-kind and in-place replacement of existing functional bulkheads in non-vegetated wetlands are consistent with NYSDEC General Permit 1-13-001 and would not require an Individual Permit. It is noted that forms must be submitted to the NYSDEC to obtain coverage under this permit, including a Request for Authorization form and a Permission to Inspect the Property form.
Article 25 permits will be necessary for the proposed plugging of existing outfalls as well as the installation of check valves into existing structures. If the current bulkheads are not situated in identified vegetated tidal wetlands then the proposed bulkhead replacements in these locations are consistent with the terms of the NYSDEC General Permit for Bulkhead Removal and Replacement (assuming no increase in height of the bulkhead) an individual permit for these improvements is not necessary. As stipulated in the general permit the bulkheads must be replaced in-kind and in-place and may be up to 18 inches higher in elevation than the existing bulkhead. If the height of the proposed replacement bulkhead is to exceed 18 inches above the existing elevation the project will need to apply for an Individual Permit.
The addition of an outfall located within the bulkhead will require an Individual Article 25 Permit and may potentially be considered a “Major Project” by the NYSDEC which would require a period of public review. For projects that include an increase in stormwater runoff the applicant must demonstrate the upland storage has the capacity to handle runoff produced by a five-year storm event. The remaining improvements proposed may be outside of NYSDEC jurisdiction if the bulkhead was in-place prior to August 20, 1977 and is still functional.
1 NYSDEC Division Fish, Wildlife and Marine Resources Tidal Wetlands Land Use Regulations Part 661.4 May 2000.
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If the addition of stormwater structures and/or the replacement of the pipe would occur outside of NYSDEC Article 25 jurisdiction and would reduce the overall discharge from the positive system then the work would not require a NYSDEC Article 25 permit.
An Article 25 Tidal Wetlands Permit Application requires the submission of a completed Joint Application Form, Short Application Form, and the Permission to Inspect Property Form, which grants the NYSDEC permission to inspect the project location. Bulkhead replacements and repairs seeking coverage under the NYSDEC General Permit require the submission of a completed Request for Authorization Form. Other information submitted to the NYSDEC with the required forms includes a location map, photographs of the project location, a copy of the NYSDEC Tidal Wetlands Map for the project site, and a project plan that includes a cross-sectional view.
Article 24 The New York State Department of Environmental Conservation (NYSDEC) regulates freshwater wetlands under Article 24 of the Environmental Conservation Law (ECL). NYSDEC regulated freshwater wetlands are illustrated in Figure 6. Jurisdictional limits for freshwater wetlands are established in 6NYCRR Part 663 and generally include setbacks/distances of 100 feet from the wetland boundary (vegetated).
Generally, Article 24 Individual Permits will be required for select proposed drainage improvements within the study area of the Village of Amityville. Projects for which permits will be necessary include the closing of existing outfalls, the modification of existing outfalls to include new check-valves, replacement of existing outfall pipes, installation of new outfalls and the removal of invasive Phragmites (Phragmites australis). Provided no sediment from construction activities were to enter the drainage system, the addition of structures outside of the 100 foot wetland adjacent area to positive drainage systems that discharge to a freshwater wetland would not be subject to NYSDEC jurisdiction as the new structures would effectively reduce the overall discharge to the wetland.
An Article 24 Freshwater Wetlands Permit Application requires the submission of a completed Joint Application Form, Short Application Form, and the Permission to Inspect Property Form, which grants the NYSDEC permission to inspect the project location. Other information submitted to the NYSDEC includes a location map, photographs of the project location, a copy of the NYSDEC Freshwater Wetlands Map for the project site, and a project plan that includes a cross-sectional view.
Town of Babylon
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The Town of Babylon has established its local laws collectively known as the “Code of the Town of Babylon”. Within these laws, the Town has created a department known as the “Town of Babylon Department of Environmental Control” to oversee all matters relating to activities that affect the environment in the Town. This Department shall supervise and control all waterways of the Town of Babylon. Chapter 99, known as the “Town of Babylon Coastal Erosion Hazard Area Law” provides guidelines to implement and administer a coastal erosion management program pursuant to Article 34 of the NYSDEC. This law provides standards and procedures as well as regulates land use and development activities in coastal areas subject to coastal flooding and erosion.
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Figure 5 Map of Tidal and Freshwater Wetlands
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6.2 DESCRIPTION OF VARIOUS STRATEGIES AND IMPROVEMENTS
The strategies and improvements are broken into four distinct areas:
A. Flooding due to storm surge/storm tide, B. Normal variations in high tide; C. Flooding due to rainfall; and D. Combination of high tides and rainfall.
Some of these strategies and improvements may be implemented in more than one area and may be combined.
A. FLOODING DUE TO STORM SURGE/STORM TIDE
Flooding due to storm surge/storm tide is associated with an abnormal rise in water level, over and above regular high tides which are caused by a severe storm event with high winds, wave action and low pressure. Storm surge is produced when water is being pushed toward the shore by the forces of the winds. The maximum potential storm surge for a particular location depends on a number of different factors. Storm surge is sensitive to the slightest changes in storm intensity, forward speed, size, angle of approach to the coast, central pressure and the shape and characteristics of coastal features such as bays and estuaries.
Storm tide occurs when there is a storm surge associated with astronomical high tide. This rise in water can cause extreme flooding in coastal areas along the south shore of Long Island resulting in storm tides reaching up to 4 feet or more.
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B. HIGH TIDES
Occasionally and as much as twice a month, high tides levels reach higher than normal levels and cause flooding in low lying areas. The areas that are low lying and below elevation 5 foot are susceptible to this type of flooding. Typically during this kind of event, tidal water from the canals backs up into the drainage outfall pipe and fills the drainage system thus, flooding the low lying community areas within that drainage watershed. The majority of the flooding in the study area has been determined to be from the tidal conditions.
C. FLOODING DUE TO RAINFALL
Some areas are affected by rainfall only, where storm surge or tidal influences are not of concern. Roadways or properties within these areas have relatively flat profiles with some areas with poorly pitched curb and gutter and distressed pavement that causes localized ponding due to rainfall. These areas with localized ponding is typically short term, and eventually drains into the drainage systems or infiltrates into the ground, and therefore are not seen as a major causes for concern as compared to the large majority of other areas that receive the tidal related flooding.
D. COMBINATION OF HIGH TIDES AND INUNDATION OF RAINFALL
All low lying areas are effected by high tides during substantial rain events. Tidal water from the canals backs up into the drainage outfall pipes and fills the drainage systems. With the drainage system full of tidal water, the rainfall is unable to be picked up by the drainage inlets and conveyed to the adjacent canal. The lack of check valves and insufficient stormwater capacity due to the tidal influence results in flooding of the local streets and neighborhoods.
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6.3 PROPOSED IMPROVEMENTS
Various general proposed improvements were developed to determine assessment, required environmental permits and general impacts. These solutions may be utilized for different types of projects or may be combined to create a single, larger project. Below is a list of each general non-site specific proposed improvement.
ASSESSMENT OF ALTERNATIVE PERMITS REQUIRED IMPACTS BENEFITS The installation of new This type of work will require a The proposed improvement vinyl bulkheads would NYSDEC Article 25 Individual Permit, would be beneficial in protect the roadways and an US Army Corps (USACE) NWP #2 preserving the road; it is recommended that or NWP #13 (location dependent), however, if the adjacent they be built at a and may require individual NYS residents do not raise their recommended elevation Department of State (NYSDOS) bulkheads, storm surge will of 2 feet above the Coastal Consistency Concurrence. overtop the privately- current street elevation The NYSDOS has granted general owned bulkhead potentially and this would prevent Coastal Consistency Concurrence for making these Installation of the majority of storms NWP #2 and NWP# 13, both of which improvements less New from overtopping and require Pre-construction beneficial. Bulkheads flooding the community. notification, if the structure will be placed in an artificial canal. Individual Coastal Consistency Concurrence will be needed for work not located within an artificial canal. Other local permits (such as building permits and Village wetland and waterway authorizations) may be required. The extent of the repairs This type of work will require Repairing the damaged to the bulkhead varies per authorization under the NYSDEC bulkhead would allow it to location, but this work General Permit for Bulkhead Removal function as originally would allow the bulkhead and Replacement (GP-1-13-001), and designed and extend its Repair Existing to function as originally coverage under USACE Nationwide service life; however, it Bulkheads intended. Permit #3 for which NYSDOS has would not address storm granted General Coastal Consistency surges and abnormal high Concurrence (therefore, individual tides, due to the existing concurrence is not required). height of the bulkhead.
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ASSESSMENT OF ALTERNATIVE PERMITS REQUIRED IMPACTS BENEFITS By constructing a Depending on year in which the Construction of a sidewalk concrete sidewalk behind bulkhead was installed and the behind the bulkhead would the bulkhead, any current state of the bulkhead (i.e., extend the service life of overtopping of waves functional, partially functional or the bulkhead. would minimize the scour failed), a NYSDEC Tidal Wetland expected, would preserve Permit may be necessary to authorize Prevent Scour the bulkhead and extend work within a wetland adjacent area. on Landside of the service life of the Bulkheads that are currently Bulkheads bulkhead. functional and which were constructed prior to August 1977 would limit NYSDEC jurisdiction to the bulkhead. Areas landward of the bulkhead would not be regulated in this situation. Installation of check Depending on the location of the This work would require valves in the existing check valves, this type of work may additional work on the drainage system would require a NYSDEC Article 25 Tidal existing drainage system so prevent tidal waters from Wetland Permit, coverage under that water cannot enter the backing up into the USACE Nationwide Permit #7, drainage system at other drainage system and individual NYSDOS Coastal locations as groundwater Install Check flooding low lying areas. Consistency Concurrence and other rises with the tide. Due to Valves local permits. the size of the check valves, a new structure must be installed to house the check valve, and this adds cost to the alternative.
Cleaning and repairing the This type of work may require a These structures and pipes drainage structures and NYSDEC Article 25 Tidal Wetland will not stay clean for an pipes will allow the Permit or a NYSDEC Article 24 extended period of time. drainage system to Freshwater Wetland Permit if the Additional maintenance function as originally outfall structure or associated intake costs would be incurred to Clean and designed. structures are located within the keep these systems clean Repair Pipes NYSDEC jurisdictional areas, coverage and functioning properly. and Drainage under USACE Nationwide Permit #7, Structures Individual NYSDOS Coastal Consistency Concurrence and other local permits (such as Village building permits and wetland/waterway authorizations).
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ASSESSMENT OF ALTERNATIVE PERMITS REQUIRED IMPACTS BENEFITS Lining of drainage pipes is This type work may require a NYSDEC The pipe run must be a less invasive way of Article 25 Tidal Wetland Permit, suitable for this type of repairing leaks in drainage coverage under USACE Nationwide repair, no major damage pipes. Lining pipes helps Permit #7 Permit, individual NYSDOS and minor cracks or to prevent infiltration of Coastal Consistency Concurrence and openings between tidal water to backup and other local permits (such as Village sections of pipe, otherwise Lining of flood low lying areas. This building permits and the repair will not work. Drainage Pipes improvement should be wetland/waterway authorizations). The cost is fairly high, but used in conjunction with is offset by the cost of check valves. excavation, backfill, new pipe and restoration for the alternative of installing a new pipe. Replacing damaged pipe This type work may require a NYSDEC Depending on the will allow the drainage Article 25 Tidal Wetland Permit. A location, depth, and system to function as USACE permit will be required if any restoration required, the originally designed. materials will enter the waters of the cost will increase United States or if work within the significantly. waters of the United States is needed. The need for NYSDOS Coastal Replace Consistency review is dependent upon Damaged the application for a USACE Individual Pipes Permit or for coverage under a Nationwide Permit and other local permits (such as Village building permits and wetland/waterway authorizations). Coordination and review with appropriate utilities such as LIPA/PSEG/National Grid and others, would also be necessary. Raising roads to the new This type of work may require a High costs due to full design elevation will NYSDEC Article 25 Tidal Wetland reconstruction of the reduce the flooding in low Permit and other local permits (such as entire roadway, including lying areas as the rims of Town/Village building permits and curb, sidewalk, driveway, drainage structures would wetland/waterway authorizations). drainage, restoration onto be higher than the tide The work would have to meet HUD private property and Raising surge, storage capacity of Uniform Relocation Act requirements. potential installation of Roadways the system could be Coordination and review with yard drains as well as the increased and the appropriate utilities such as cost of easements and the roadway would be LIPA/PSEG/National Grid and others, associated compensation. passable. would also be necessary.
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ASSESSMENT OF ALTERNATIVE PERMITS REQUIRED ADVERSE IMPACTS BENEFITS Adding additional This type of work would require a Adding structures and drainage structures to the NYSDEC Article 25 Tidal Wetlands pipe to a drainage system existing drainage system permit if the proposed structures were would require significant will increase the overall located within tidal wetland restoration of the Adding capacity of the system jurisdiction. Other local permits may roadways and areas in the Structures to and reduce flooding be necessary (such as Village building vicinity. The effective Drainage during significant rain permits and wetland/waterway depth of the structure will System events and/or periods of authorizations). Coordination and be influenced by the high tide. review with appropriate utilities such groundwater elevation. as LIPA/PSEG/National Grid and others, would also be necessary.
Replacing existing pipes This type of work may require a If the entire system with larger diameter pipes NYSDEC Article 25 Tidal Wetland needed replacement, the would increase the Permit, coverage under USACE cost would be very high. If capacity of the drainage Nationwide Permit #3 and/or #7, the outlet of the drainage system allowing it to Individual NYSDOS Coastal Consistency system is high the pipe Replacing handle larger storms and Concurrence and other local permits may not have enough Existing Pipes tidal events. (such as Village building permits and cover required. with Larger wetland/waterway authorizations). Diameter Pipes Coordination and review with appropriate utilities such as LIPA/PSEG/National Grid and others, would also be necessary.
Adding leaching If located within NYSDEC Article 25 Ground water is high in structures or leaching Tidal Wetlands jurisdiction, a permit this area and not much fields to the drainage from the NYSDEC would be required. It leaching capacity would system increases the is noted that the NYSDEC requires a be realized. overall capacity of the minimum of two feet of vertical system and helps store separation from groundwater, and 100 stormwater during times feet of horizontal separation from the Add Leaching of high tide when there tidal wetlands boundary. Coordination Fields aren’t ways to release. It and review with appropriate utilities also reduces the quantity such as LIPA/PSEG/National Grid and of stormwater runoff by others, would also be necessary. allowing filtration and quality of the water by settling of solids.
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41 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
ASSESSMENT OF ALTERNATIVE PERMITS REQUIRED ADVERSE IMPACTS BENEFITS
A bio-retention area Depending on the location of the Based on the information would reduce stormwater project a NYSDEC Article 25 Tidal reviewed, there aren’t from the positive Wetlands Permit of a NYSDEC Article many areas owned by the drainage system, 24 Freshwater Wetlands Permit may Town/Village within the removing stormwater be necessary. study area that would Adding Bio- that can be affected by permit the construction of a Retention tidal influence. It also large bio-retention area. Areas reduces the quality of Small areas at the street stormwater runoff by ends could be constructed, allowing filtration and but there are design settling of solids. concerns of overflow and location of existing bulkhead. A retention basin would Depending on the location of the There aren’t many areas eliminate some project a NYSDEC Article 25 Tidal owned by the Village in stormwater and allow it Wetlands Permit of a NYSDEC Article the study area that would to infiltrate into the 24 Freshwater Wetlands Permit may permit the construction of Adding ground. Depending on be necessary. a large retention basin. Retention the amount of flooding Basins and the size of retention basin some or all runoff would be eliminated.
By changing older and/or This type work may require a NYSDEC Many structures in the outdated frames and Article 25 Tidal Wetland Permit if work study area are Suffolk Changing grates and/or curb would occur within NYSDEC Tidal County type structures Frames and openings, the inlet Wetland jurisdiction. Depending on with only curb openings. Grates and/or capacity of the drainage the location of the project, coverage These basins do not allow Curb Openings structure will be under USACE Nationwide Permit #7, for the frame and grate to on Existing improved. Individual NYSDOS Coastal Consistency be installed easily and a Structures Concurrence and other local permits full reconstruction of the may be necessary. drainage may be required. By adding catch basin This type of work may require a These filter/debris filters/debris removal NYSDEC Article 25 Tidal Wetland removal systems need systems in drainage Permit if work occurs within NYSDEC proper maintenance. If Adding structures, debris within Tidal Wetland jurisdiction. Depending left too long and debris Filter/Debris the stormwater would be on the location of the project, builds up, the system Removal trapped and could be coverage under USACE Nationwide could fail, sending the System to removed periodically by Permit #7, Individual NYSDOS Coastal debris into the drainage Drainage Village Maintenance Consistency Concurrence and other system or the debris could Structures Forces. local permits may be necessary. clog the inlet and not allow water to enter the drainage system.
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ASSESSMENT OF ALTERNATIVE PERMITS REQUIRED ADVERSE IMPACTS BENEFITS
A pump station can pump Depending on where the stormwater is A typical pump station water from one location being pump to and from, (i.e., if in a uses electricity to run the to another. canal, wetland or water body or within pump. If water gets into the adjacent regulated area), this type the pump station or there Construction work may require a NYSDEC Article 25 is a power outage, the of a Pump Tidal Wetland Permit and other local pump will not work, thus Station permits. not solving the flooding problem. There are also ongoing maintenance and staffing costs associated once the pump is installed.
See Appendix 5 for details for these Improvement Details.
Potential Alternatives
43 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
7.0 IDENTIFIED PROBLEM AREAS, ASSOCIATED CONSTRUCTION COSTS AND BENEFITS
The Proposed Projects for the Village of Amityville have been analyzed in terms of costs, public impact, long term sustainability and resiliency benefits. Those projects where the total project cost of an investment that yields high returns while reducing government and private expenditures as a result of future storms will be highly recommended. Other benefits to be considered include decreased risk/vulnerability to flooding; economic benefit to maintaining residential property values; environmental benefits by improving stormwater quality; and health and social benefits from maintaining clear access to schools and medical facilities during emergency events and allowing for emergency responders to gain access to the neighborhoods. This analysis will assist in determining which projects are priorities over others.
While the projects proposed would not eliminate all flood risks, it would reduce the possibility, especially for typical storm events and high tide phases. Extreme storm events will still present flood risks as was evidenced with Superstorm Sandy.
7.1 IDENTIFIED PROBLEM AREAS A. FLOODING DUE TO STORM SURGE/STORM TIDE
Storm surge/storm tide is the abnormal rise in water level, over and above the regular tide, caused by a severe storm such as a hurricane or nor'easter. Storm tide is when the water level rises due to a combination of high tide moon phase, storm surge from an incoming storm and the possibility of wave influences. Large waves can raise coastal water levels and ride on top of the storm surge potentially causing extreme damage.
The method of preventing damage to the community caused by storm surge/storm tide is to put a barrier between the water and the community. Barriers can be different in material and design such as a wetland (swamps, estuaries, and mud flats) which act as sponges; levees or dykes which prevent the water from reaching the community; or bulkheads which also prevent water from reaching the community. The wetlands, levees and/or dykes are not feasible in the study area and are outside the scope of the project. The land required to build a wetland is not available and the funding necessary to accomplish either of these tasks would be daunting. Bulkheads can be constructed/reconstructed to a height that would prevent a certain type storm and accompanying surge, but there are drawbacks to this concept.
If a major storm event such as a major hurricane or nor’easter, struck the study area and the tides associated with the storm rose to elevation 10, approximately
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44 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
50% of the study area would be flooded (see Appendix 3 for the Hurricane Surge Zone Map). The guidance for construction/reconstruction of bulkheads is to raise them to the Base Flood Elevation (BFE) plus two feet. The BFE for the Village of Amityville varies from 6 to 7 feet. In addition, the Community Risk and Resiliency Act (CRRA) makes provisions for certain State funded programs to incorporate considerations of future physical climate risks caused by storm surges and sea- level rise. As part of this act, the DEC developed 6 New York Codes, Rules and Regulations (NYCRR) Part 490 which will establish sea-level rise projections. Although the DEC has not completed its projections to date, projected sea-level rise should be incorporated into the elevations determined for bulkhead elevations. The Draft DEC sea-level rise projections for Long Island for the year 2020 is 6”. This projection will raise the BFE to 6’–6” to 7’–6”. However, raising all new bulkheads to the new BFE height plus 2 feet (8’-6” to 9’-6”) is not reasonable at all locations when the current street elevation may be as low as elevation 3. In addition, if the Village raise their bulkheads to this new elevation, every homeowner adjacent to the canals/creeks will have to raise their bulkhead as well. This will be a heavy burden for each one of these homeowners and will affect their viewshed and their property value and is beyond the funding and scope of this project. Therefore; each location will be reviewed independently, but for estimating purposes, bulkheads will be raised two feet (2’) above current street elevation.
By constructing new bulkheads where none already exist, replacing the existing bulkheads and reconstructing damaged bulkheads and installing check valves in all drainage systems to prevent the tide from back flowing into the community, the study area would be subject to diminished flooding events with little to minor impact to the community.
Currently, the Village has a project in construction for the replacement of existing bulkheads and installation of drainage structures and check valves on Village owned street ends and outfalls. The following locations are under contract at the time of this Report:
Group A Group C Location 1 Morris Street West) Location 9 South Bay Ave Location 2 Morris Street (East) Location 10 Fleming Canal Location 3 South Ketcham Ave Location 12 Cooper Ave Location 4 Berger Ave Location 14 Griffing Ave Location 16 Bayside Canal Group B Location 5 Braham Ave Group D Location 6 Stuart Ave Location 17 Purdy Lane Location 7 Lebrun Ave Location 18 Bayside Place Location 8 Norman Ave Location 19 New Point Place Location 21 South Bayview Ave
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45 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
Group E Group F Location 22 Richmond Ave Location 11 Perkins Ave Public Dock Location 13 Coles Ave Location 15 MacDonald Ave Location 20 Meadow Lane
Even though the cost for raising bulkheads can be very high, the study will suggest that bulkheads owned by the Village of Amityville be investigated for the potential to be raised to some extent to protect the Village’s investment into its roadways and appurtenances. This may encourage adjacent homeowners to also raise their bulkhead.
Comparison of Sea-Level Rise, BFE and Height of Proposed Bulkheads Current 2020 2050 Sea-Level Rise Projection - 6 in 16 in Base Flood Elevation 6 ft 6 ft – 6 in 7 ft – 4 in Proposed Bulkhead Varies 8 ft 8 ft Height • Sea-level rise displayed is medium rise projection and taken from the Community Risk and Resiliency Act and DEC’s 6 NYCRR Part 490
B. FLOODING DUE TO HIGH TIDES
Occasionally and as much as twice a month especially during moon tides, high tide levels reach higher than normal levels causing flooding in low lying areas. This type of flooding has been identified as the most often cause of flooding in the study area. Low lying areas are susceptible to this type of flooding.
Typically, during this kind of event, tidal water from the creeks and canals backup into the drainage outfall pipe, fills the drainage system and then discharges the tidal waters out of the drainage basin grates and onto local roads at the low points, thus flooding the low-lying community areas within that drainage watershed. To address this kind of event, an alternative of installing in-line check valves with pretreatment structures and/or catch basin filter bags upstream of outfall pipes will prevent tidal water from entering into the drainage system and backing up into the system as noted above. The drainage structures and pipes within the drainage system affected must be in good working condition and the system will need to be cleaned and any damage to the system will have to be repaired. A key component to this is the installation of filter/debris removal systems that will prevent the check valves from being clogged and/or stuck in an opened or closed position. Other alternatives considered include raising the roads above the high tide level, and eliminating unnecessary existing outfalls by connecting multiple positive drainage systems. The combining of drainage outfalls reduces the amount of check valves and filter/debris removing system required thus reducing the continued ongoing maintenance associated with these improvements.
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46 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
Areas where the installation of inline check valves are proposed include:
Street/Road Adjacent Streets/Roads MacDonald Ave Between Grand Central Ave and S Bayview Ave Norman Ave South of Richmond Ave Shore Road Shore Drive West Dewey Ave Dead End Dewey Ave Mincher Place Mincher Place Dead End Lebrun Ave South of Richmond Ave Braham Ave South of Richmond Ave Central Ave North of Shore Road Richmond Ave Between Norman Ave and S Bay Ave Grand Central Ave North of Dewey Ave Grand Central Ave South of Dewey Ave Grand Central Ave Near Dead End Grand Central Ave At Dead End South Ketcham Ave Between Morris St and Dead End South Bay Ave Mid-Block Meadow Lane East South of Bayview Ave Bayside Place East South of Bayview Ave Folkstone Road At Bunny Lane Swartout Place South of Shore Road Riverside St At Dead End Hamilton St Mid-Block Bayside Ave Dead End Unqua Place Dead End James Caples Park At Beach
Areas where the road raisings are proposed include:
Street/Road Adjacent Streets/Roads MacDonald Ave Between Grand Central Ave and S Bayview Ave Riverside Ave From Perkins Ave to Griffing Ave Shore Road Shore Road, Shore Drive West, Berger Ave Dewey Ave Dewey Ave and Mincher place Norman Ave Richmond Ave to Dead End
C. FLOODING DUE TO RAINFALL
Flooding due to rainfall only is relatively minor, which is typically localized ponding along the roadways and some private properties. These areas that receive localized ponding are generally short term, where stormwater eventually flows into
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47 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
the drainage systems or is infiltrated into the ground and may be caused by the undersized system. Adding drainage structures and/or increasing pipe size typically increases the capacity of those drainage systems
Location that receives flooding due to rainfall only:
Street/Road Adjacent Streets/Roads Richmond Ave South of Riverleigh Place Richmond Ave At Robbins Ave Ireland Place At Ocean Ave Ocean Ave At Coles Ave Bayside Ave At Anita Place Bourdette Place At Ocean Ave Cooper Ave At Turner Place Cooper Ave At South Bayview Ave Riverside Ave South of Merrick Road
D. COMBINATION OF HIGH TIDES AND RAINFALL
Flooding due to the combination of high tides and rainfall happens occasionally, where a significant storm such as the 10-year storm will create major flooding in areas that are below an elevation of 5 ft. During an event where high tides and extreme rain intensity occurs, tidal water from the canals backs up into the drainage outfall pipe and fills the drainage system while the rainfall is picked up by the drainage inlets and is blocked from exiting the drainage system due to the tidal influence. The result of this is flooding of the low lying community areas within that drainage watershed. Locations listed in Section B above are affected by the combination of high tides and rainfall.
7.2 ASSOCIATED COSTS There can be several different methods of recommended mitigations to the flooding and drainage deficiencies within the study area; each having vastly different costs associated with them including; Construction Cost, Engineering Cost, Environmental Permitting Cost, and Right-Of-Way Cost. The Construction Cost includes a 20% contingency, all materials, time, equipment, and labor to build the improvement as well as construction inspection costs. Engineering Cost includes the cost of the engineering design of the improvement, direct labor cost, overhead, and fixed fees. Environmental Permitting will be required for several different recommended projects which requires a fee for the necessary environmental permits. N&P will assume that the Engineering Cost and the Environmental Permitting Cost will be 20% of the total Construction Cost. Right- Of-Way Cost includes any cost associated with the purchase of property to construct the alternative. Although permanent ROW acquisition of property is not
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48 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018 anticipated, N&P will assume a Right-Of-Way Cost of $40/SF to purchase property and a cost of $15/SF for any permanent/temporary easements.
A. COST FOR INSTALLING NEW VINYL BULKHEADS
The study area is densely populated with homes and structures adjacent to the bay, creeks, or canals; therefore, installation of new and/or reconstruction of existing bulkheads are viable solutions to flooding conditions experienced in the study area. As discussed previously, the extent of raising the height of the bulkhead will be two feet (2’) above current street elevation. Work included in rebuilding or constructing a new bulkhead will include the cost for removal of the existing bulkhead if one exists; and construction of a navy style bulkhead made with vinyl sheeting which cost more up-front but will have a lower life-cycle cost making them more cost effective in the long term. Vinyl sheeting will last more than 50 years, where timber sheeting will need replacement of various wood components due to the elements and wood borers and will have an average life of 25 years.
Repairing of existing bulkheads will be done in kind to keep the aesthetics of the bulkhead. These repairs will consist of replacement of rotted or deteriorating wood sheets and other wood elements with similar wood material. Both new and repaired bulkheads, when located on Village owned property, will have a concrete sidewalk installed on the landside of the bulkhead to prevent any scouring caused by wave action overtopping the bulkhead.
B. COSTS OF INSTALLATION OF CHECK VALVES
The purpose of a check valve is to allow only one-way flow of, in this case, stormwater, to exit the drainage system and not allow tidal water back flow into the drainage system. This concept is proposed for many drainage system outfall locations present throughout the study area. The idea is that stormwater can exit the positive drainage system through an outfall with a properly installed check valve during non-high tide events while managing to prevent any back flow of tidal water into the drainage system during high tide.
The effectiveness of any check valve is directly associated with the contractor’s ability to install the check valve correctly and the required maintenance of the
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49 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018 drainage system so debris does not inhibit the proper functionality of the check valve.
The most common check valves currently in use are the duck bill check valve and the in-line check valve. Both of these work by closing when the tidal influence is greater than the pressure within the drainage system and opening only when the pressure within the drainage system is greater than the pressure of the tidal influence. The duck bill check valve is mainly installed at the outfall pipe and sticks out beyond the bulkhead or headwall which will inhibit boat traffic in and around this check valve.
Many existing outfalls are in the backyards of residents on Village owned easements which inhibit maintenance of these check valves. Village maintenance forces would be required to enter onto private property and many residents are not home during these hours, inhibiting access to the check valve. The in-line check valve is more commonly used these days because it is installed inside the existing outfall pipe of the drainage system and does not protrude beyond the bulkhead or headwall, thus not interfering with boat traffic. Inline check valves can also be installed in new drainage structures adjacent to or on Village owned streets. This makes maintenance easier and will not require access onto local resident’s backyards and therefore, recommended in this study.
In-Line Check valve Duck Bill check valve
In addition to the check valve, a stormwater treatment structure or catch basin filter bags will be installed upstream of the new check valve. The purpose of these debris removal/treatment systems is to remove debris and oils from the road runoff, cleaning the stormwater prior to discharge into the adjacent canal and to remove debris that may clog or damage the check valve and make it inoperable. The use of both type of debris removal/treatment systems will be reviewed for each
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50 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018 drainage system individually. Catch basin filter bags will typically be installed on small drainage systems and stormwater treatment structure will typically be installed where their high cost is cost effective (typically larger systems with large watershed areas).
C. COSTS OF RAISING ROADS
Due to the rising tidal water and ground water influences, raising a road could ideally bring the roadway elevation out of harm’s way for high water levels during a high tide, storm surge and storm event, along with allowing for additional storm water storage during typical rain events. Existing stormwater is typically collected, stored, and/or piped under the existing roadway, sidewalks and utility areas and either dissipates into the ground or travels to a specified outfall location. The larger the area under the roadway that is available to work with, the higher the potential to be able to design for more stormwater storage.
In order to effectively perform a road raising, ideally all buildings and/or homes need to currently be set at a high enough elevation above the proposed road elevation; however, yard drains can be installed on homeowner’s properties to pick up stormwater that ponds in low lying areas of residential properties. In addition, GOSR has indicated that all road raisings will require 100% approval of every homeowner and temporary work easements with compensations to each homeowner affected by the road raising under the Uniform Relocation Act (URA). These requirements could deter any road raising alternative.
The cost of road raising would include reconstruction of the roadway including sidewalks, curbs, pavement, and reconstruction of the drainage system, including check valves and debris removal/treatment systems, which can be extremely expensive as well as restoration of private property and the cost of the associated temporary work easements. Since this alternative is so expensive, it should only be looked at when the benefit outweighs the costs. To be a truly beneficial and effective road raising, the road should be raised to the Base Flood Elevation (BFE); however, this would place many of the adjacent properties far below the road elevation, hence a minimum elevation of 6 inches to 18 inches above the current road elevations would be recommended. By building the proposed road to this new elevation, during storm events, the road should remain passable.
D. COSTS OF REDESIGN OF THE DRAINAGE SYSTEM
A review of the existing drainage systems has identified inefficiencies and some inadequate design. In order to correct flooding problems in the past, it appears that drainage structures and pipes have been constructed and attached to existing drainage systems without regard to pipe size, pipe slope and system capacity. There are several locations where the downstream pipes are smaller in size than
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51 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018 upstream pipes, where pipes were installed back pitched or where the amount of stormwater cannot be contained and/or conveyed to the outfall because the watershed area is now greater than initially designed. In other areas, multiple small systems with few catch basins and an outfall into a canal were constructed to relieve flooding.
Correcting such inefficiencies would allow the drainage systems to perform as originally designed or connecting these small systems and constructing a larger system would create the potential for more storage of stormwater. Correction of these inefficiencies would require extensive work such as cleaning of the existing drainage system; replacing damaged pipe and structures; replacing existing pipes with larger diameter pipes due to increase capacity; adding drainage structures, leaching fields or retention basins to increase capacity; installing debris removal systems to keep the drainage system clean and functioning properly; and milling and asphalt resurfacing of the roadway to improve gutter flow of stormwater on the roadway.
E. INSTALLATION OF GREEN INFRASTRUCTURE
Green infrastructure is a cost effective, resilient approach to managing stormwater impacts while providing benefits to the surrounding community. Typical stormwater drainage systems include pipes and structures that contain stormwater and move the stormwater to areas away from the urban environment into engineered collection systems or discharged into nearby water bodies. Green infrastructures typically reduce and treat stormwater at its source and provides environmental, social, and economic benefits by using soil and plants to absorb and filter stormwater. Typical examples of these green infrastructures include rain gardens, bio-swale or bio-retention areas, green streets as well as others. For this project, bio-swale and/or bio-retention areas are being considered. These areas are depressions in the existing ground that capture runoff and remove contaminants and sedimentation from the runoff. The bio-retention area or bio- swale area consists of grass, wetland vegetation, a sand bed, a ponding area, an organic layer or mulch layer, planting soil, and plants. The sand bed reduces the velocity, filters particulates, and spreads flow over the length of the bio-retention area. Aeration and drainage of the planting soil are provided by the deep sand bed. The ponding area provides a temporary storage location for runoff prior to its evaporation or infiltration. The organic or mulch layer also filters pollutants and provides an environment conductive are for the growth of microorganisms, which degrade petroleum-based products and other organic material. Typically, these areas will be located at street ends adjacent to the outfall pipe for the drainage system.
A further review of the Village of Amityville did not reveal that locations for bio- retention or bio-swale areas are available especially in the areas of need. With only small areas by street ends and a few small unoccupied parcels available for this
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52 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018 treatment, construction of bio-retention or bio-swale areas would not provide the necessary corrective measures that would yield the returns for the investments expended; therefore, this alternative has been dismissed from further investigation.
Typical Bio-Swale or Bio-Retention Area
In addition to the bio-retention areas, it is proposed to install stormwater treatment structures and/or catch basin filter bags that will remove trapped trash, debris, sediment, oils. and hydrocarbons from the stormwater runoff prior to discharging the runoff into the canals and eventually into the bay. While these treatment systems will remove trapped trash, debris, and sediment, they will require regularly scheduled maintenance. Regular maintenance can be an easy process accomplished with the use of a vacuum truck.
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53 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
Vortechs Stormwater Treatment Structure CDS Stormwater Treatment Structure
Typical Stormwater Treatment Structure
Typical Catch Basin Filter Bag
F. INSTALLATION OF PUMP STATIONS
Pump stations are facilities that house pumps and equipment to pump stormwater from a low-lying area to another location. Pumps are turned on during stormwater events where flooding occurs. Stormwater would be pumped through a system of
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54 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
pipes to another drainage system or into a nearby canal. Pump stations run on electricity which may pose an issue during a storm event due to a power outage.
Traditional pump stations used for stormwater are costly and are price by the pump flow rate. The average pump station required for an average drainage system during the peak hour flow rate would be rated a 10 to 24.99 Million Gallons per Day (MGD) pump costing approximately $12.5 M.
One local municipality on Long Island had installed a pump station system at a troubled location that constantly flooded. In discussions with this municipality, they indicated that this alternative failed leading them to dismiss any future use of pump stations. This being the case due to the poor performance as noted by this local municipality; the reliance on electrical power and the usual electrical outages associated with major storms; the maintenance and manpower required to run the pump station; and the extreme high cost associated with the pump required to be effective during the peak hours of flooding, this alternative has been dismissed from any further discussions.
G. COMBINATION OF ALTERNATIVES
Some areas flood due to multiple reasons and it may take a combination of alternatives to prevent flooding from occur at these locations. A drainage system may require larger pipes, more storage, an inline check valve and stormwater treatment structure in order to prevent flooding. Each drainage system will be examined and corrective measures will be included to relieve flooding in the adjacent community.
In some areas, it may be best to combine drainage systems and provide only one (1) outfall pipe rather than multiple drainage systems with multiple outfall pipes. In this instance, connecting two adjacent drainage systems by rebuilding and/or adding drainage pipes and structures would be proposed. Instead of having to prevent tidal waters from backing up at two location, now only one location needs to be remedied. Once the combined drainage system is constructed, only one (1) check valve and one (1) debris removal/filter system would be required minimizing maintenance efforts and overall cost.
7.3 BENEFITS Each proposed project will be prioritized based on the several factors which will include the total project cost, the number of homes immediately affected by the project, the significance of the roadway, and the elevation of the project location
The proposed projects are each estimated for the overall cost consisting of the construction cost, the engineering cost, environmental permitting cost, and the Right-Of-Way cost. The construction cost for the proposed projects includes and an itemized list of the major items of work for the proposed alternatives included
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55 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018 in that project and unit prices from recent bid history which include adjustments for materials, equipment and labor costs; an additional fifteen percent (15%) for the Work Zone Traffic Control (WZTC) required; an additional ten percent (10%) for survey and stakeout; four percent (4%) for the contractor’s mobilization; and a twenty five percent (25%) contingency cost. The construction cost does not include any costs associated with utility replacement, relocation, or repair; and maintenance costs. Right-Of-Way Cost includes any cost associated with the purchase of property to construct the alternative. Although permanent ROW acquisition of property is not anticipated, N&P will assume a Right-Of-Way Cost of $40/SF to purchase property and a cost of $15/SF for any permanent/temporary easements. The actual cost for any Right-Of-Way for any project will be determined during the preliminary design of that project.
Along with the construction cost, the number of homes affected by the project and the significance of the roadway will be major contributors to the priority of the project. The homes affected will be approximate and subjective as it will be closely associated with the storm intensity, the storm duration and the tidal influence and will be based on the observed storms during the development of the drainage Study Report and discussions with the Village. The significance of the roadway will be based on the potential use of the roadway for an evacuation route, for access to neighborhoods by emergency response vehicles or for use by the community not necessary living in that location such as access to a facility like a school, a shelter or a firehouse.
The majority of the flooding observed was located in a low lying area of the study area. Typically, areas from elevation 10 and lower have been observed as the areas that are affected most frequently, as much as twice a month, by flooding events like high tides and/or non-major storms.
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56 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
8.0 PROPOSED PROJECTS
8.1 PROPOSED PROJECTS The significant projects listed in this section have been rated based on the benefits listed in Section 7.3 of this report. GOSR has indicated that approximately $1.68M is to be used for construction of the selected projects.
It is recommended that the Village of Amityville research funding opportunities for an annual maintenance Drainage Clean/Repair/Replace Contract that will keep the existing drainage system in a state of good repair. Drainage structures and pipes will need to be cleaned, repaired, and/or replaced as necessary. Drainage filter inserts and stormwater drainage treatment structures will need cleaning. Bulkheads will need to be inspected and repaired/replaced as necessary. It is recommended that these annual contracts clean/repair/replace all the drainage structures and pipes within the study area within a 4 to 5-year period.
The following proposed projects were found to mitigate the flooding impacts generated by a 1-year, 10-year and 100-year storm over a 24-hour period (based on the Suffolk County Type II Rainfall distributed design storm) and tidal surge/storm tide of the highest annual tide cycle from Sandy Hook (NAVD88).
Proposed Projects
57 Comprehensive Storm Drainage Improvements Study for the Village of Amityville Village of Amityville, Suffolk County, New York June 2018
8.1.1 PROPOSED PROJECTS AND RECOMMENDATIONS
DRAINAGE ISSUES, SUGGESTED SOLUTIONS, AND ASSOCIATED COSTS - AMITYVILLE SUGGESTED SOLUTION (IN GREEN) SOLUTION INCLUDED IN OTHER PROPOSED PROJECT (IN YELLOW) SOLUTION(S) CRITICAL HOMES LOC. OVERALL ANTICIPATED COST STREET NAME DRAINAGE ISSUE(S) 1. SHORT TERM SOLUTION (S.T.S.) FACILITIES IMPACTED / NO. FOR CONSTRUCTION 2. LONG TERM SOLUTION (L.T.S.) IMPACTED PROTECTED
THROUGHOUT THE VILLAGE THERE ARE APPROXIMATELY 55 1. THIRTEEN (13) PROPOSED HIGH PRIORTY CHECK-VALVES TO BE INSTALLED ON THE EXISTING OUTFALLS THAT DISCHARGE STORM WATER INTO EXISTING OUTFALLS DEPICTED ON THE PLAN IN RED. HIGH PRIORITY LOC. VARIOUS THE WATERWAYS; 16 OF WHICH HAVE EXISTING CHECK- $630,000.00 P-1 CHECK-VALVE VALVES; 20 OF WHICH ARE CURRENTLY BEING INSTALLED VARIES VARIES 2. ELEVEN (11) ADDITIONAL LOWER PRIORTY CHECK-VALVES ARE TO BE INSTALLED ON THE INSTALLATIONS UNDER THE 'AMITYIVLLE WATERFRONT RESILIENCY EXISTING OUTFALLS DEPICTED ON THE PLAN IN ORANGE. LOW PRIORITY LOC. IMPROVEMENTS' PROJECT; 19 OF WHICH ARE IN NEED OF A $550,000.00 PROPOSED CHECK-VALVE. DURING CERTAIN STORM SURGE/HIGH TIDE SCENARIOS, 1. ALL TOWN OWNED BULKHEADS IN NEED OF REPAIR OR REPLACEMENT ARE BEING CERTAIN EXISTING VILLAGE OWNED BULKHEADS HAVE BEEN RECONSTRUCTED UNDER THE 'AMITYVILLE WATERFRONT RESILIENCY IMPROVEMENTS' OVERTOPPED AND INFILTRATING BY TIDAL WATER. THIS PROJECT. WATER HAS BEEN KNOWN TO INUNDATE MUCH OF THE VARIOUS TOWNS ROADWAYS AND INFRASTRUCTURE ONCE BREACHING NO ADDITIONAL BULKHEAD CONSTRUCTION IS PROPOSED. P-2 BULKHEAD THE BULKHEAD. NO CONSTRUCTION ANTICIPATED VARIES N/A REBUILDS UNDER THE 'AMITYVILLE WATERFRONT RESILIENCY IMPROVEMENTS' PROJECT, THE VILLAGE IS HAVING 22 EXISTING BULKHEADS RAISED AND REPLACED
DEPENDING ON LOCATION THROUGHOUT THE VILLAGE, 1. SEE PLAN FOR SUGGESTED ROAD RAISING AREAS. 1. SHORE DR W. / SHORE DR SPECIFIC ROADS VARY IN ELEVATION. SUCH ROADS THAT ARE A 2. NORMAN AVE LOWER LYING ELEVATIONS ARE AFFECTED DUE TO GROUND 3. UNQUA PL WATER, POOR DRAINAGE AND TIDAL WATER FLOODING. 4. RICHMOND AVE (END) 5. DEWEY AVE 6. MINCHER PL 7. GRAND CENTRAL AVE (S/O DEWEY) VARIOUS P-3 8. MACDONAL AVE VARIES VARIES ROAD RAISING 9. GRAND CENTRAL AVE NEAR MACDONAL AVE 10. S. BAYVIEW AVE NEAR MACDONALD AVE 11. MEADOWN LN 12. AVENUE S. 13. RIVERSIDE AVE - PERKINS AVE TO GRIFFING AVE EXISTING ROADWAY AND TRIBUTARY WATER SHED EXCEEDS 1. INSTALL 14 EACH, 8' DIA. X 4' DEEP LEACHING BASIN STRUCTURES W/ PIPE TURNER PLACE & LOC-1 THE EXISTING DRAINAGE CAPAICTY SIGNIFICANTLY. CONNECTIONS ALONG TURNER PLACE, COOPER AVE AND S BAYVIEW AVE TO CAPTURE $160,000.00 RESIDENTIAL 6 COOPER AVE STORM WATER PRIOR TO ANY LOW LYING AREAS.
EXISTING ROADWAY AND TRIBUTARY WATER SHED EXCEEDS 1. INSTALL 6 EACH, 8' DIA. X 4' DEEP LEACHING BASIN STRUCTURES FOR INCREASED THE EXISTING DRAINAGE CAPAICTY SIGNIFICANTLY. CAPACITY AND STORAGE.
2. CONNECT LEACHING BASINS ALONG THE SOUTH SIDE OF BAYSIDE AVE VIA OVERSIZED $150,000.00 7 DRAINAGE PIPE. BAYSIDE AVE & LOC-2 RESIDENTIAL ANITA PLACE 3. CONNECT TO EXISTING POSITIVE SYSTEM ON RICHMOND AVE VIA EXISTING CATCH BASIN ON THE S/E/c OF BAYSIDE AVE AND RICHMOND AVE. 4. INCREASE PIPE SIZE AND BASIN INFRASTRUCTURE FOR ENTIRE POSITIVE SYSTEM ALONG RICHMOND AVE. $1,700,000.00 N/A
EXISTING ROADWAY AND TRIBUTARY WATER SHED EXCEEDS 1. REMOVE EXISTING CATCH BASIN ON N/E/c OF MOLE PLACE AND RICHMOND AVE. THE EXISTING DRAINAGE CAPAICTY SIGNIFICANTLY. 2. INSTALL 2 EACH, 8' DIA. X 4' DEEP LEACHING BASIN STRUCTURES AND CONNECT TO $25,000.00 1 EXISTING POSITIVE SYSTEM ON RICHMOND AVE VIA EXISTING CATCH BASIN ON WEST SIDE MOLE PLACE & LOC-3 OF RICHMOND AVE, NORTH OF MOLE PLACE. RESIDENTIAL RICHMOND AVE 3. INCREASE PIPE SIZE AND BASIN INFRASTRUCTURE FOR ENTIRE POSITIVE SYSTEM ALONG RICHMOND AVE. $1,700,000.00 N/A
EXISTING ROADWAY AND TRIBUTARY WATER SHED EXCEEDS 1. INSTALL 14 EACH, 8' DIA. X 4' DEEP LEACHING BASIN STRUCTURES W/ PIPE RESIDENTIAL/ COLES AVE & LOC-4 THE EXISTING DRAINAGE CAPAICTY SIGNIFICANTLY. CONNECTIONS ALONG COLES AVE AND OCEAN AVE TO CAPTURE STORM WATER PRIOR TO $160,000.00 MINOR 4 OCEAN AVE ANY LOW LYING AREAS. COMMERCIAL
FLOODING OCCURS ON MACDONAL AVE PAST THE CROSS 1. INSTALL CHECKVALVE (UNDER VARIOUS PROPOSED CHECK-VALVE LOCATIONS PROJECT) STREETS OF GRAND CENTRAL AVE AND S. BAYVIEW AVE. AT THE EXISTING OUTFALL ON MACDONALD AVE BETWEEN GRAND CENTRAL AVE AND S. DEPENDING ON TIDAL SURGE ELEVATIONS, FLOODING IS BAYVIEW AVE. $43,750.00 100+ CAUSED BY BACKFLOW OF TIDAL WATER THROUGHT THE EXISTING UN-CONTROLLED DRAINAGE SYSTEM AS WELL AS 2. INSTALL FILTER BAGS ON TWO CATCH BASINS CONNECTED TO EXISTING OUTFALL. OVER THE BULKHEADS AT THE BAYSIDE/NEW POINT CANAL AND S. BAYVIEW/GRAND CENTRAL CANAL; THE WORST OF 3. RAISE THE BULKHEAD AT THE CANAL ON S. BAYVIEW AVE BETWEEN BAYSIDE PLACE AND WHICH IS LOCATED ON MACDONAL AVE AT THE LOWEST NEW POINT PLACE (UNDER CONSTRUCTION CURRENTLY - 'AMITYVILLE WATERFRONT POINT BETWEEN GRAND CENTRAL AVE AND S/ BAYVIEW AVE. RESILIENCY IMPROVEMENTS' PROJECT) RESIDENTIAL/ MAC-1 MACDONALD AVE 4. RAISE A SECTION OF MACDONALD AVE FROM THE WEST END OF THE GRAND CENTRAL AVE INTERSECTION TO THE EAST END OF THE S. BAYVIEW AVE INTERSECTION (1,000FT +/- MUNICIPAL ); RAISE SECTION OF GRAND CENTRAL AVE AND S. BAYVIEW (EACH 625' +/-). $2,220,000.00 100+ 5. INSTALL 11 NEW CATCH BASINS CONNECTED TO OUTFALL.
6. UPGRADE EXISTING OUTFALL PIPE TO ACCOMODATE INCREASED DISCHARGE CAPACITY OF POSITIVE SYSTEM.
** NEED PRIVATE PROPERTY ON SOUTH SIDE OF MACDONAL AVE TO RAISE PRIVATELY OWNED BULKHEADS TO ASSIST IN ALLEVIATING FLOODING ISSUE DRAINAGE ISSUES, SUGGESTED SOLUTIONS, AND ASSOCIATED COSTS - AMITYVILLE SUGGESTED SOLUTION (IN GREEN) SOLUTION INCLUDED IN OTHER PROPOSED PROJECT (IN YELLOW) SOLUTION(S) CRITICAL HOMES LOC. OVERALL ANTICIPATED COST STREET NAME DRAINAGE ISSUE(S) 1. SHORT TERM SOLUTION (S.T.S.) FACILITIES IMPACTED / NO. FOR CONSTRUCTION 2. LONG TERM SOLUTION (L.T.S.) IMPACTED PROTECTED FLOODING OCCURS MIDWAY DOWN THE BLOCK AT THE 1. INSTALL NEW CHECKVALVE IN EXISTING STRUCTURE PRIOR TO EXISTING OUTFALL EXISTING LOW POINT. THIS ROADWAYS TRIBUTARY WATER MIDBLOCK (AT THE EXISTING LOW POINT). ALSO INSTALL CHECK-VALVE AT EXISTING SHED IS SERVICED BY TWO VASTLY UNDERSIZED NON-POSITIVE OUTFALL TO THE WEST OF GRAND CENTRAL AVE (IF NOT COMPLETED UNDER VARIOUS DRAINAGE STRUCTURES AS WELL AS TIDAL WATER CHECK-VALVE PROJECT). INFILTRATING THE EXISTING UNPROTECTED OUTFALL. 2. INSTALL 8 EACH, 4' x 4' CATCH BASIN STRUCTURES PRIOR TO THE LOW POINT ON NORMAN AVE. $405,000.00 27 NORMAN NAC-1 3. INSTALL AND CONNECT PROPOSED CATCH BASINS ON NORTH AND SOUTH SIDE OF RESIDENTIAL AVE STREET WITH OVERSIZED DRAINAGE PIPE. PIPE USED TO MAXIMIZE STORMWATER STORAGE AMOUNT.
4. INSTALL FILTER BAGS ON ALL CATCH BASINS CONNECTED TO THE POSITIVE SYSTEM. 5. RAISE ALL OF NORMAN AVE - 1,500' SECTION (150' WEST OF RICHMOND AVE & 200' EAST OF THE DEAD END) AND REDUCE/ELIMINATE LOW POINT (MIN. ELEV. 3.0'). INCLUDES $1,500,000.00 27 ASSOCIATED DRAINAGE INSTALL.
FLOODING OCCURS IN THE LOW SPOT IN THE N/W/c OF SHORE 1. INSTALL A CHECK-VALVE ON THE EXISTING OUTFALL LOCATED BETWEEN HOUSE No. 45 DRIVE AND SHORE ROAD. FLOODING CAUSED BY NO & 49. BACKFLOW PREVENTION ON THE EXISTING OUTFALL ON $42,250.00 20 SHORE ROAD BETWEEN HOUSE No. 45 & 49, ACTING AS A 2. INSTALL FILTER BAGS ON ALL EXISTING STRUCTURES CONNECTED TO OUTFALL. CONDUIT FOR THE TIDAL WATER. DEPENDING ON TIDAL SURGE 3. RAISE THE EXISTING BULKHEAD AT THE STREET END OF BERGER AVE (UNDER ELEVATIONS, WATER CAN BE OBSERVED OVERTOPPING THE CONSTRUCTION CURRENTLY - 'AMITYVILLE WATERFRONT RESILIENCE IMPROVEMENTS' NARRASKETUCK YACHT CLUB BULKHEAD AS WELL AS THE PROJECT) RESIDENTIAL/ SD-1A SHORE BERGER AVE STREET END BULKHEAD. MINOR SD-1B DRIVE 4. RAISE SECTION OF SHORE ROAD, SHORE DRIVE AND BERGER AVE TO ELIMINATE LOW COMMERCIAL ROADWAY ELEVATIONS (MIN. ELEV. 3.0') $1,200,000.00 20 5. INSTALL 17 EACH, 4' x 4' CATCH BASIN STRUCTURES CONNECTED WITH OVERSIZED PIPE FOR INCREASED CAPACTIY AND VOLUME DISCHARGE.
** NEED PRIVATE PROPERTIES & COMMERCIAL BUSINESSES TO RAISE PRIVATELY OWNED BULKHEADS TO ASSIST IN ALLEVIATING FLOODING ISSUE
FLOODING OCCURS AT THE INTERSECTION OF DEWEY AVE AND 1. INSTALL CHECK-VALVES (UNDER VARIOUS PROPOSED CHECK-VALVE LOCATIONS MINCHER PLACE AS WELL AS WITHIN THE CUL-DE-SAC ON PROJECT) AT THE EXISTING OUTFALLS AT DEWEY AVE CUL-DE-SAC, DEWEY AVE AND $100,000.00 4 DEWEY AVE. FLOODING IS DUE TO TIDAL SURGES MINCHER PLACE AND THE DEAD END OF MINCHER PLACE. INFILTRATING THE EXISTING OUTFALLS WITHOUT ANY DEWEY 2. INSTALL PRE-TREATMENT FILTER BAGS ON ALL EXISTING STRUCTURES ON DEWEY AVE. DM-1 BACKFLOW PREVENTION AS WELL AS OVERTOPPING OF RESIDENTIAL AVE BULKHEADS, DEPENDING ON STORM SURGE ELEVATIONS. 3. INSTALL 4 EACH, 4' x 4' CATCH BASIN STRUCTURES WITH FILTER BAGS FOR PRE- $850,000.00 4 TREATMENT. REPROFILE/REBUILD EXISTING ROAD END OF MINCHER PLACE TO ACCOMMODATE NEW STRUCTURES AS WELL AS RAISE THE ROAD 6 INCHES.
FLOODING OCCURS ALONG BOTH GUTTER LINES (EAST & 1. RAISE SOUTHERN SECTION OF RIVERSIDE AVE AT GRIFFING AVE TO ELIMINATE EXISTING WEST) ON RIVERSIDE AVE DUE TO BACKFLOW OF TIDAL WATER LOW AREA. THROUGH THE EXISTING DRAINAGE SYSTEM AND OVER $1,375,000.00 20 RIVERSIDE TOPPOING OF BULKHEADS. THE SOUTHERN END OF RIVERSIDE 2. INSTALL 8 EACH, 4' x 4' CATCH BASIN STRUCTURE CONNECTED WITH OVERSIZED PIPE RAC-1 RESIDENTIAL AVE AVE AT GRIFFING AVE FLOODS EVEN WORSE DUE TO LOWER ALONG RIVERSIDE AVE, FOR INCREASE CAPACITY OF SYSTEM. ELEVATIONS. 3. SUPER-ELEVATE EAST SIDE OF ROADWAY TO CREATE ONE LANE PASSABLE ROUTE W/ INCREASED PIPING CAPACITY AND RAISED RESIDENTIAL R-O-W. $500,000.00 20
RECOMMENDED PROJECTS BASED ON BUDGET $1,585,000.00 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
8.2 FUNDING SOURCES Below is a table of funding sources relevant to the projects that are recommended in this study. Village officials should contact agency representatives to discuss funding priorities and specific eligibility requirements. Over the years, the Village has applied for and received both FEMA mitigation funding and should continue to apply under the various FEMA grant opportunities for the recommended projects. At the next opportunity, the Village should update Village of Amityville section of the FEMA approved “Suffolk County Multi- Jurisdictional Hazard Mitigation Plan” to include those projects recommended in this report that are not included in the County’s 2014 revised plan.
The Village should pursue New York Rising funding for design and construction for the recommended projects.
POTENTIAL FUNDING Funding Sources Program Eligible Activities SOURCES ID No.
A HUD 1. Community a. Construction funding Development Block resulting from Amityville Grant Drainage Study
B Federal Emergency 1. Flood Mitigation a. Various projects to prevent Management Assistance Program flooding and protecting public Agency (FEMA) and private resources, e.g. road 2. Hazard Mitigation thru NYS Division and property elevations, Grant Program of Homeland culverts, buyouts, projects must Security & 3. Pre-Disaster have a positive benefit-cost ratio, Emergency Mitigation Grant 75/25 funding Services (DHSES) Program (formally NYS SEMO) 4. Severe Repetitive Loss Program (only for private properties)
Proposed Projects
58 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
POTENTIAL FUNDING Funding Sources Program Eligible Activities SOURCES ID No. C FHWA 1. Surface a. Road Reconstruction and administered by Transportation Drainage/Impervious Surfaces NYS DOT thru System (STS) Stormwater Outflow devices. Suffolk County Roads must be designated on 2. MAP-21 DPW- Federal Aid Urban system Maps
Federal Funding administered by b. Enhancements to the NYS DOT / New Transportation System- York Metropolitan streetscapes, historic Planning Council preservation, environmental (NYMTCC) improvements
D New York State 1. Consolidated a. Drainage curb, sidewalks, Dept. of Highway permeable paving
Transportation Improvement
Program (CHIPS) b. Drainage, curb, sidewalks, 2. Multi-Modal permeable paving Program c. Replace/rehabilitate bridges 3. Bridge & Culvert & culverts Program
E Dormitory 1. State & Municipal a. Various construction / Authority of the Facilities Program economic development projects State of New York (DASNY) F New York State 1. Water Quality a. Municipal Wastewater Department of Improvement Treatment Environmental Project (WQIP) b. Municipal Separate Storm Conservation (NYSDEC) Sewer Systems (MS4s) c. Nonagricultural Nonpoint Source Abatement and Control
d. Aquatic Habitat Restoration
e. Water Quality Management
f. Green Innovation Practices
Proposed Projects
59 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
POTENTIAL FUNDING Funding Sources Program Eligible Activities SOURCES ID No. New York State 1. Green Innovation a. Innovative Stormwater Environmental Grant Program Management projects: structural Facilities & non-structural practices for G Corporation Clean Water State sediment, pesticide and fertilizer Revolving Fund control that may include 2. Federal Section permeable pavement, bio- 212- Point Source – retention, stormwater street trees, etc., Funding available at Loan Financing 90% federal and 10% local. 3. Federal Section 319- Non-Point b. Water Quality improvement Source-Loan Projects- Loans and Grants for Financing Point Source projects such as STPs and Sewers and Non-Point 4. New York State Source projects for stormwater Infrastructure management, land acquisition if Improvement Act related to preserving water quality- projects must be municipally owned-bio- retention, permeable surfaces. Provision for non-municipal
projects.
Low-interest Loans- for green or non-green projects/Low Interest loans for short and long-term financing. STPs Sewers-Design & Construction c. New Program that is incorporated into the State G (CONT.) Revolving Fund. Grants available for the above.
Proposed Projects
60 COMPREHENSIVE STORM DRAINAGE IMPROVEMENT STUDY THE VILLAGE OF AMITYVILLE June 2018
9.0 RECOMMENDED PROJECTS
GOSR has indicated that approximately $1.68M is to be used for construction of the selected projects.
Based on the results of this study of the Village of Amityville and in coordination with GOSR and the Village of Amityville the recommended projects are as follows:
• Installation of the High Priority Check Valves at the Construction Cost of approximately $630,000. This project will provide a benefit to a multitude of the Village’s residents by eliminating flooding in low lying areas caused by the bi- monthly high tides backflowing into the drainage system and onto local roads and neighborhoods.
• Installation of the Low Priority Check Valves at the Construction Cost of approximately $550,000. This project will also provide a benefit to a multitude of the Village’s residents by eliminating flooding in low lying areas caused by the bi- monthly high tides backflowing into the drainage system and onto local roads and neighborhoods.
• Norman Avenue Drainage Capacity Project at the Construction Cost of approximately $405,000. During high tides and rain events, road runoff and tidal backflow inundates Norman Avenue to a point just south of Richmond Avenue hindering the 30+ families from leaving their homes and emergency services from getting to their homes. By increasing the drainage capacity on Norman Avenue and installing an inline check valve on the drainage outfall into the canal east of Norman Avenue, the rain will be contained in the new enlarged drainage system, the tide backflow will be prevented, and Norman Avenue will be passible.
Total Construction Cost $1.585M
Recommended Projects
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