Hawkinsville Remediation and Removal Study

Background

In 2007, the Dam Safety Section of the New York State Department of Environmental Conservation, Division of Water, notified the Regulating District of certain deficiencies at the Hawkinsville Dam. Additionally, it has been determined that the dam has insufficient spillway capacity to safely pass the project design flow.

In October 2010, the Board of Hudson River-Black River Regulating District (Board) hired a consultant to complete a Remediation and Removal Alternatives Assessment. The consultant completed a report in March 2012 which included a preliminary assessment of the physical and hydraulic condition of the project and presented four concepts for increasing the discharge capacity of the facility. Additionally, as an alternative to remediation, the consultant developed a preliminary assessment of dam removal.

On April 10, 2012 Regulating District engineering staff presented the consultant’s report on the Remediation and Removal Alternatives Assessment, including a discussion of each remediation option and the removal alternative, to the Regulating District Board.

Click here for information on the Remediation and Removal Alternatives Assessment Report

In May 2012 staff recommended further study of Remediation Option 4 (an inflatable weir) and the removal alternative. The Regulating District Board accepted the staff recommendation to conduct a final study which would refine Option 4 and the removal alternative.

Final Study and Design

In April 2013, the Board hired Kleinschmidt Associates, PA, PC (Kleinschmidt) to complete a final study of Remediation Option 4 and the removal alternative (Hawkinsville Remediation and Removal Final Study and Design). The final study will evaluate the advantages and impact, and identify the social, economic, environmental, recreational, physical, and regulatory issues, considerations and benefits, associated with both the remediation and removal alternative.

In Phase 1 of the study, Kleinschmidt will conduct a records review and site assessment to gain an understanding of the environmental, socioeconomic, recreational, aesthetic, physical, and regulatory issues related to repair or removal of the Hawkinsville Dam. The engineering effort will include development of a draft report and presentation to the Board. Kleinschmidt will make a presentation of the alternatives to the Board and the public at two Public Outreach Meetings. A Final Report will be developed, incorporating Board comments and reflecting the Board’s consideration of public comments.

It is anticipated that, upon Board consideration of the Final Report and a staff recommendation, the Board will select either the remediation or removal alternative.

In Phase 2 of the project, it is anticipated that a Final Design will be developed, and either reconstruction or deconstruction of the dam will follow.

Click here for a Summary of Project Tasks

For additional information contact Robert Foltan, P.E., Chief Engineer, at the Regulating District’s Albany office.

Any questions or comments regarding the proposed remediation or removal may be directed to the Regulating District Albany office at hrao@hrbrrd.com.

Natural Resources and Wetlands Assessment November 2013

The Hudson River – Black River Regulating District and its consultant engineering firm for this project, Kleinschmidt, are completing an evaluation of the Hawkinsville Dam. This evaluation will examine and compare two alternatives proposed to bring the dam into compliance with state dam safety regulations. The evaluation will explore both remediation/repair and removal of the dam and spillway. To further the objectives of the evaluation, a natural resources/wetland assessment, field work, and data gathering will need to occur. Kleinschmidt’s team of engineers will be conducting topographic, bathymetric, and wetland surveys beginning the week of November 11. The following links provide maps of the areas to be included in the field surveys.

Topographic Survey Limits Map
Hydrographic Survey Limits Map
Potential Wetland Areas
Hawkinsville Tax Mapping

Hawkinsville Dam Remediation/Removal Project Update January 2014

Kleinschmidt Associates, PA, PC (Kleinschmidt) is completing a study to evaluate and compare remediation of the Hawkinsville Dam to a dam removal alternative. Remediation or removal of the dam is necessary to bring the Hawkinsville Dam into compliance with Department of Environmental Conservation (DEC) Dam Safety Regulations, and to address the facilities inadequate spillway capacity.

The Regulating District’s engineering consultant, Kleinschmidt, has completed a records review, survey, site assessment, as well as a natural resource assessment, and is completing site evaluations to gain an understanding of the environmental, socioeconomic, recreational, aesthetic, physical, and regulatory issues related to repair or removal of the Hawkinsville Dam.

In preparation for development of a draft report, and to evaluate the proposed repair and removal options, Kleinschmidt updated a hydraulic modeling effort concerning the spillway design flood (SDF) and the hazard classification for Hawkinsville Dam.

In summary, the results of the hydraulic modeling indicate that the bridge abutments (Hawkinsville Road), which are located downstream of the dam, will significantly affect the elevation of the water in the river. The hydraulic model shows that the restriction of flow caused by the narrow opening at the bridge will control the elevation of the river, immediately upstream of the bridge, during flood events. The influence of the bridge abutments on the water surface elevation near the Hawkinsville Dam suggests that the SDF should be revised and the hazard classification should be changed.

Kleinschmidt recommends that Hawkinsville Dam be reclassified as a Class A hazard dam (lower hazard potential then current classification of “B”) and that the SDF be reduced from 21,450 cubic feet per second (cfs) to the 100-year flood, or 14,300 cfs. The Regulating District is making a formal request for the DEC Dam Safety to consider the recommendation and to reduce the SDF and hazard classification.

The hazard reclassification and the reduction in the SDF will likely minimize the effort needed to remediate the dam.

The draft report, which was previously scheduled to be submitted to the Board at the end of January 2014, will be delayed by approximately 45 to 60 days to allow the findings and results of the hydraulic modeling to be submitted to DEC Dam Safety for review.

Please see Kleinschmidt’s Hawkinsville Hydraulic Modeling memorandum for a detailed discussion of the recommendation to reduce the hazard classification and SDF.

Hawkinsville Dam Remediation/Removal Project Update April 16, 2014

Kleinschmidt Associates, PA, PC (Kleinschmidt) completed hydraulic modeling of the Hawkinsville Dam in January 2014 to evaluate and determine the spillway design flood (SDF). Modeling of the SDF resulted in a recommendation to request that the Department of Environmental Conservation (DEC) reduce the hazard classification assigned to Hawkinsville Dam. The hydraulic modeling report and request to reduce the hazard classification was submitted to the DEC in March.

In a letter dated April 2, 2014, the DEC Division of Water, Bureau of Flood Protection and Dam Safety accepted Kleinschmidt’s hydraulic report and recommendation to reduce the hazard classification at Hawkinsville Dam. The DEC considers the Hawkinsville Dam to be a Class A – low hazard structure.

A dam with a Class A – low hazard classification must safely pass the 100-year flood (SDF). If the structure is unable to pass the design flood, then remediation of the structure, which allows the facility to safely pass the SDF, must be completed.

Kleinschmidt is completing its assessment of the safety of the facility and making a determination regarding the need for remediation.

A draft report, which compares the impacts and cost of remediation and removal, is scheduled to be submitted to the Board at the beginning of May 2014.

Project Schedule – Phase I – Final Study

  • Consultant Information Review – Completed
  • Site Assessment – Completion May 2014
  • Draft Study Report Submitted to the Board – May 30, 2014
  • Draft Report Available for Public Comment (June Board Meeting) – June 10, 2014
  • Board Considers Public Comments (July Board Meeting) – July 10, 2014
  • Consultant Prepares Final Report – July 11 – August 15, 2014
  • Board Receives Final Study Report – August 18, 2014
  • Board Selects an Alternative (September Board Meeting) – September 9, 2014

Hawkinsville Dam Remediation/Removal Project Update June 11, 2014

Kleinschmidt Associates, PA, PC (Kleinschmidt) presented the first draft of the Hawkinsville Dam Final Study on the remediation and removal alternative to bring the Hawkinsville Dam into compliance with Department of Environmental Conservation dam safety regulations. A copy of the draft report may be downloaded from the following link.

Draft Hawkinsville Dam Final Study

A copy of the Kleinschmidt presentation may be found here: Kleinschmidt Presentation June 10, 2014.

Project Schedule – Phase I – Final Study

  • Board Receives Draft Report – May 30, 2014
  • Kleinschmidt Presentation of Draft Report – June 10, 2014
  • Provide Report for Public Comment – June 11, 2014
  • Board Considers Public Comments – July 2014
  • Public Comment Meeting – Sseptember 9, 2014
  • Consultant Prepares Final Report – September 2014
  • Board Receives Final Study Report – September 2014
  • Board Selects an Alternative – October 2014

Hawkinsville Dam Remediation/Removal Project Update September 10, 2014

The Board of Hudson River – Black River Regulating District unanimously passed a motion to pursue the remediation alternative for the Hawkinsville Dam. The Board has authorized Regulating District staff to begin the next phase of the project which includes obtaining the necessary permits, authorizing the engineering consultant to begin final design, and to establish a long-term agreement for use of land not currently part of the project.

The final report of the Hawkinsville Dam Final Study on the remediation and removal alternative is available through the following link:

Hawkinsville Dam Final Study