Warwick Reservoir Dams

Tectonic has been appointed to serve on an annual basis as the Village of Warwick’s consultant for dam safety compliance. As such, Tectonic is responsible for performing safety inspections and engineering assessments, and preparing updates to Emergency Action Plans and annual certifications for the Village’s three water supply reservoir dams.

Over the course of fifteen years, Tectonic has provided design phase geotechnical, civil, environmental, structural, and surveying services for the Village’s Upper, Middle and Lower Warwick Reservoir Dams. Engineering services provided include:

• Alternatives Analysis for Improvements to three reservoir dams
• Engineering Assessment for Upper and Lower Reservoir Dams
• Dam Breach Analyses for Upper and Middle Reservoir Dams
• Design of repair of leaking water supply main beneath the Lower Reservoir Dam embankment
• Design of repairs to the Upper Reservoir Dam and Spillway damaged by Hurricane Irene
• Design and permitting for rehabilitation of the Lower Reservoir Dam and Spillway and reservoir dredging
• Design and permitting for dredging of the Lower and Middle Reservoirs
• Preparation of Inspection & Maintenance Plans for all three dams
• Preparation of Emergency Action Plan for the Lower Reservoir Dam
• Performance of Safety Inspections for all three dams
• Inspection of the construction for the Lower Reservoir Dam rehabilitation and reservoir dredging projects
• Hydraulic Analysis

Waterford Drainage Improvements Evaluation

The Village of Waterford, located on the west side of the Hudson River in Saratoga County, experienced catastrophic flooding during Hurricane Irene in August 2011. A neighborhood of 55 residences at the north end of the Village was inundated by rising water and suffered losses. The Village requested $1 million in Community Development Block Grant – Disaster Relief (CDBG-DR) funding under the New York Rising Community Reconstruction (NYRCR) program to complete the improvements described as the “Wetland Drainage System Improvements” in the Waterford NYRCR Plan.

Tectonic worked with the Governor’s Office of Storm Recovery to appraise the request, perform an engineering and environmental project feasibility review, evaluate alternatives, outline regulatory requirements, and recommend viable approaches to control or mitigate the flooding impacts with the objective of achieving resiliency.

The final study recommended the provision of backflow prevention and construction of a municipal separate storm sewer trunk to improve drainage, reduce flooding, and increase access to first responders. A more extensive solution involving wetland detention behind a railroad embankment was found to be only marginally more effective at reducing flooding during high-frequency storm events.

Route 17M Wawayanda Water & Sewer

The Town of Wawayanda Water and Sewer District #1 was formed, designed, and permitted for 200,000 gallons per day using water purchased by Inter-municipal Agreement from the City of Middletown.

The project consisted of over 10,000 linear feet of sewer and water piping ranging from 6 to 18 inches in diameter along with a wastewater pumping station. This visionary project made current development along the key corridor possible (auto retail, warehouse, affordable housing, hotels, 650 MW power plant).

Tectonic provided survey, subsurface investigation, engineering design (including conceptual design development, preparation of design plans, reports, specifications, cost estimates, bid documents), and regulatory permitting with NYSDEC, NYSDOT and Orange County Department of Health.

Tectonic also provided construction phase support services which included resident inspection of trench excavation, sheeting, placement of all piping and manhole structures, directional drilling, pressure testing/disinfection, and restoration.

The project included thirteen crossings beneath busy NYS Routes 6 and 17M using horizontal directional drilling techniques, benefiting from Geotechnical services including detailed test borings along the sewer and water line alignments.

NYC DDC Water Main and Sewer Projects

Tectonic has worked with the New York City Department of Design & Construction for twenty years providing Resident Inspection Engineering (REI) services for various Water Main and Sewer Projects located throughout the NYC area. NYC streets are routinely rehabilitated due to damage caused by storms and normal wear and tear. Recent projects include:

• Reconstruction of Peck Slip, Manhattan – Worked with utility companies, residents and contractors to help rebuild this densely populated area devastated in the aftermath of Superstorm Sandy. This included the installation of water main and hydrants, sewers, catch basins, chute connections, manholes and reconstruction of cobblestone roadway.

• Trunk Water Mains at 8th Avenue, Manhattan – Scope involved the installation of trunk water mains in the Jackson Square area in addition to private utilities relocation and capital work to connect Water Tunnel #3 to the distribution system in Manhattan.

• Reconstruction of College Point Boulevard, Queens – An extensive project to extend and replace distribution water mains along College Point Blvd. This impacted various communities and the project team ensured the public notification of service disruption complied with Agency protocol and in a timely manner. Community outreach included survey of the affected area to establish critical water needs.

• Installation of Storm and Sanitary Sewers in Beach 29th Street, Queens – The proximity of the project site to the beach required Stormwater Pollution Prevention Plan (SWPP), corrosion control

Haverstraw Redevelopment Utilities & Stormwater Management

The Harbors at Haverstraw, a 544-unit residential building, is part of the waterfront brownfield redevelopment project along the Hudson River in the Village of Haverstraw. As part of the Harbors Project, the Joint Regional Sewer Board of Haverstraw (JRSB) required that GDC commit to upgrade the existing JRSB Dr. Girling Drive Sanitary Sewer Duplex Pump Station. JRSB sought capacity to handle future flows and the elimination of sub-standard pumping capacity when one pump was offline.

Tectonic advanced the design of the Girling Pump Station Upgrade in preparation for bidding, and assisted GDC with the bidding process. The design was approved by the JRSB and Rockland County Department of Health. The design included replacement of two dry pit mount pumps with larger 110 hp dry pit mount, new generator, controls and electrical service. Tectonic provided engineering construction support through the completion of construction and start up.

The design required careful consideration of bypass sequence and facilities to maintain operation of the existing pump station building and facilities during construction and startup of the upgrade.

Wickham Water District

The Wickham Water District serves approximately 350 homes in which the water supply facilities are located on six separate sites on the District edges.

Tectonic served as the Town Engineer for Warwick and assisted the Town with the completion of several rehabilitative and new construction projects for the Wickham Water District.

Tectonic provided survey, engineering design, permitting, analytical testing, subsurface, and construction administration and inspection services for the following projects:

  • District expansion approval
  • Repair of an aging 200,000 gallon water storage tank
  • Construction of a new 100,000 gallon water storage tank
  • Chemical treatment system and building for sequestering metals
  • Greensand Filter system for iron and manganese removal
  • New treatment/disinfection building/distribution main
  • 2 new municipal wellsMany of the projects required careful coordination to ensure construction efforts did not impact continued water service for the existing District water users.

Great Neck Plaza Parking Lot

Tectonic worked closely with the Village of Great Neck Plaza to support the reconstruction of the Maple Drive municipal parking lot in Great Neck Plaza utilizing green infrastructure techniques.  The Village was successfully awarded a $675,000 project grant from the New York State Environmental Facilities Corporation (EFC) under their highly competitive Green Innovation Grant Program (GIGP). Existing infrastructure was improved using a “green”, sustainable approach to construction that would improve vehicle circulation and lot utilization.

Tectonic initially prepared a feasibility study that accompanied the grant to support this project. Tectonic documented environmental matters including threatened and endangered species, historic properties listed on the National Register of Historic Places, archaeologically sensitive areas, subsurface conditions, aquifers, and critical environmental areas. Green infrastructure practices were screened for compatibility with the project location and site conditions. Viable practices were further explored for prospective sizing, environmental benefit, and construction requirements. Construction inspection and materials testing will be provided during the spring of 2016.

Ultimately, a permeable pavement system was utilized to help minimize flooding in addition to reducing stormwater runoff into storm drains, waterways, and eventually the Long Island Sound. Additional green improvements included low-maintenance landscaping, LED street lighting, and solar-powered central metering in place of the outdated coin-operated metering. The parking lot project will help revitalize the Great Neck downtown community and stimulate economic development in other Long Island Communities nearby.

Glenmere Lake Dam

Glenmere Lake Dam, a large, high hazard dam, impounds a water supply reservoir with a surface area of 328 acres and drainage area of 2.4 square miles. The dam is approximately 600-feet long and consists primarily of an earth embankment with a maximum height of 24 feet, partly supported by masonry stone and reinforced concrete walls. The crest of the dam serves as a two lane paved County roadway. Glenmere Lake also provides habitat for the largest known population of the endangered, Northern Cricket Frog (Acris crepitans) in New York State.

Tectonic prepared an Engineering Assessment and Emergency Action Plan for the dam that included the following:

• Hydrologic and hydraulic analyses
• Dam breach analyses
• Inundation mapping and hazard class evaluation
• Incremental damage assessments
• Spillway capacity evaluation
• Subsurface investigation
• Stability and seepage analyses
• Topographic and bathymetric surveys

As a result of the Engineering Assessment, the spillway capacity and dam stability were found to be deficient. Tectonic performed additional studies including an evaluation of raising the dam embankment and enlarging the spillway to increase storage and spillway capacity to prevent overtopping.

Tectonic prepared permit application documents, design plans, cost estimates and construction documents to complete the necessary improvements and modifications that include modifying the alignment of the dam to reduce the length of the dam by more than 50 percent, installing a toe drain to control seepage, and replacing the existing spillway and spillway conveyance conduit.

The relocation and shortening of the dam was a unique approach that eliminated the need for costly environmental remediation, reduced impacts to the Northern Cricket Frog population and allowed construction to proceed without lowering the reservoir which would have drastically impacted the water supply and endangered species.

Construction is currently underway and Tectonic is providing resident engineering inspection and material testing services and also monitoring of the Northern Cricket Frog as required by the NYSDEC.