We bring you a full range of technical expertise and cost-effective solutions through our integrated approach to dam and levee safety, geotechnical engineering, water resources, civil engineering, and natural resources.

GZA is a recognized leader in the dam safety field and an active member in the leading professional societies/associations such as the Association of State Dam Safety Officials (ASDSO), US Society on Dams (USSD) and National Hydropower Association (NHA).

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Public & Private Water Suppliers
Federal, State and Local Government Agencies
Power
Private Dam Owners
Industrial and Commercial Impoundment Owners
Visual Inspections

Our visual inspections combine a review of available information and actual field conditions to generate a real-time evaluation of a dam/levee's condition and identification of dam/levee safety and maintenance needs. 

A GZA field reconnaissance effort for a dam safety or levee inspection is always performed by a Registered Professional Engineer. We typically utilize a team of two engineers for efficiency and safety. During the field visit, notes are taken on the standard checklist, digital photos are taken, and a site sketch is prepared. Our reports present information on the physical characteristics of the dam/levee and any deficiencies observed in the various components utilizing the report format, checklists, etc., in accordance with the specific regulatory agency's requirements. The main goals of our inspection reports are: 1) document the condition of the structure and 2) present our recommendations for improving safety, maintenance, and operability.

Expertise
  • Rope Access Inspections
  • Remotely Operated Vehicle (ROV) Inspections
  • Dive Inspections
  • State Regulatory Dam Safety Inspections
  • FERC Part 12 Safety Inspections
  • USACE Periodic Levee Inspections
Engineering Evaluations and Assessment

Our engineering evaluations are performed to evaluate hydrologic, hydraulic, geotechnical, and structural elements of the dam to determine if the structure is "compliant" or if remedial measures are required.

Our dam and levee safety engineering evaluations are typically identified during our visual inspections.  GZA's dam and levee safety engineers are well-versed in all aspects of hydrologic and hydraulic (H&H) analyses, geotechnical and structural evaluations, and gates and valves assessments. Our engineering evaluations are performed to determine if the dam/levee complies with current regulatory requirements and/or generally accepted dam/levee safety guidelines.  We are very familiar with the state and federal dam safety regulations as well as dam/levee safety design guidelines published by the USACE, FERC and USBR.

Expertise
  • Hydrologic & Hydraulic Analyses
  • Geotechnical Engineering Analyses
  • Structural Engineering Analyses
  • Gates and Valve Evaluations
  • Risk and Reliability Evaluations
Design & Construction Services

GZA’s design experience includes remediation and rehabilitation of earthen, stone masonry, timber and concrete dams and earthen levees and concrete floodwalls.

Utilizing the results of our visual inspections and engineering evaluations, GZA's dam and levee safety engineers perform comprehensive design services for our dam and levee clients. We routinely expand our engineering evaluations to the design phase of the project during a preliminary design phase where alternatives are developed and evaluated.  The preferred alternatives are chosen in a collaborative manner with our clients in a way that accounts for many factors, which include safety, cost, schedule, operations, and maintenance considerations.  Our design packages vary with the size and scale of the project, typically ranging from a limited number of drawings with construction notes to a comprehensive design that involves 30%,60%, 90% and 100% design plans, specifications, costs estimates and construction schedule submittals, followed by complete bid support services.  Our involvement during construction ranges from part-time construction observation services during critical phases of the work to complete construction administration services including full time resident engineering, submittal review, RFI response, pay requisition review and record plan development.

 

Expertise
  • Tree Removal
  • Riprap
  • Toe/Blanket Drains
  • Spillway Augmentation
  • Overtopping & Scour Protection
  • Low-Level Outlet Expansion
  • Stability Berms
  • Anchors and Toe Buttresses
  • Relief Wells
  • Foundation Grouting
  • Concrete Repairs
  • Stone Masonry Repointing
  • Design Services During Construction
  • Resident Engineering 
Emergency Action Planning and Inundation Mapping

Our emergency action planning and inundation mapping services combine the skills of our water resource engineers with our data management experts to generate efficient and easily understood emergency response documents for our clients. Over the past 25 years, GZA has prepared EAPs for over 100 high and significant hazard dams located throughout the United States.

Enormous potential energy contained in the waters of large reservoirs can cause extensive loss of life and property. Recent countrywide experiences have shown that a small dam breach can have catastrophic consequences. Emergency Action Plans (EAPs) are necessary to help respond to emergency situations associated with a sudden, rapid and uncontrolled release of water. EAPs set forth the basic procedures, duties, and responsibilities to be implemented by dam owners, operators, and key public safety personnel in the event of dam failure.

The major components of an EAP include detailed procedures for emergency identification, repair, notification, and evacuation as defined in FEMA's benchmark document, Publication P-64-Federal Guidelines for Emergency Action Planning for Dam. A challenging element of this work is the dam breach simulation and floodwave routing, which are vital to the development of Inundation Maps. GZA's staff of engineers and hydrologists is well-versed in the use of the USACE's computer simulation software, HEC-RAS, and performing complex and dynamic modeling. GZA has extensive experience producing CAD and GIS-derived color Inundation Maps.

Expertise
  • HEC-RAS Modeling 
  • DSS-Wise Modeling
  • ArcGIS
  • EAP Orientation and Table-Top Exercises
Hydropower

GZA has provided hydropower engineering services at projects from 40 kW to 900 MW in size. Our hydropower services are comprehensive, extending from feasibility studies, preliminary resource assessments, and licensing to engineering design including turbine selection and powerhouse design to FERC compliance activities include relicensing, permitting, environmental studies, FERC Part 12D Safety Inspections, PFMA Facilitation and EAP Training Exercises

Work scope includes the full range of studies and design tasks to assist in the assessment and development of hydropower projects from conception to commissioning. This includes turbine selection and physical/structural upgrades of the powerhouse and related appurtenant facilities.

GZA is experienced in the FERC hydropower licensing process. GZA is a strong client advocate and our approach to licensing issues is to provide solutions which are in the best interest of the project proponent, but we also recognize that listening carefully to both government and regulatory stakeholders can reduce contention and speed the licensing process. GZA has a wealth of experience performing invasive species investigations and monitoring and developing invasive species control plans. We are experienced in developing Exhibit F and G drawings in accordance with FERC regulations that FERC has approved. Our multi-disciplinary capabilities allow us to handle almost all aspects of FERC licensing with in-house staff.

Expertise
  • Preliminary Resource Assessments
  • Feasibility Studies
  • Facility Condition Assessments
  • LIHI Files
  • Turbine Selection
  • Part 12 Safety Inspections
  • Potential Failure Mode Analyses
  • Dam Safety Surveillance and Monitoring Plans & Reports
  • Fish and Eel Passage Design
  • EAPs
  • FERC Licensing & Relicensing
Dam Removal & Stream Restoration

GZA has been a pioneer in assisting owners with dam removal and stream restoration. In some cases, an owner may find that the a dam no longer serves its intended function and no longer is an asset.

GZA provides expertise for feasibility studies, permitting, environmental impact reporting, design and construction for removal of dams as proactive means for sound environmental restoration. Using our combined skills in natural resource sciences and engineering, GZA is an industry leader in this rapidly developing field, having successfully removed more than a dozen dams. Our clients have realized a reduction of operating costs and safety risks associated with removing their aging dams and the public has benefited from the conversion of these previously dammed streams to free-flowing conditions.

Stream stabilization has become “softer” throughout the years, focusing on bio-engineered methods in lieu of reinforced concrete or other more traditional stabilization methods. Our experience in this field enables us to provide more natural stabilization solutions which better address bank erosion, sediment loading, and water quality issues while also restoring critical aquatic habitats and fish passage such that streams return to equilibrium with their natural surroundings.

GZA has extensive experience in stream assessment and restoration design. We have experience in EPA rapid bio-assessment and Rosgen stream classification protocols in addition to having technical experts in fisheries, aquatic invertebrates, aquatic macrophytes, wetlands, and herpetiles. GZA engineers are also accomplished in stream stabilization and restoration design. Riverine services include stream assessment, stream habitat, stream restoration and design, invertebrate surveys, fisheries services, fish and wildlife passage design and stream habitat / continuity assessment. 

Expertise
  • Sediment Transport Analysis
  • Sediment Management Plans
  • Fluvial Geomorphology
Insights
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Turbid Discharge Incident At Cannonsville Dam

On July 8, 2015, the New York City Dept. of Environmental Protection (DEP) discovered a turbid discharge at the toe of Cannonsville Dam, a 2,800 ft. long, 175 ft. max. height, earthen dam constructed...
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