Memorandum
City of Lawrence
City Manager’s Office
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TO: |
David L. Corliss, City Manager
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FROM: |
Diane Stoddard, Assistant City Manager
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CC: |
Cynthia Boecker, Assistant City Manager Toni Wheeler, Director of the Legal Department Dave Wagner, Director of Utilities Philip Ciesielski, Assistant Director of Utilities Mike Lawless, Assistant Director of Utilities
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Date:
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February 24, 2009 |
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RE: |
Study Session on Bowersock Dam and Utility Issues |
Bowersock Dam 1977 Agreement and Background
The dam is owned by Bowersock Mills & Power Company. As a regulatory entity for energy providers, the Federal Energy Regulatory Commission (FERC) is involved in reviewing actions related to the dam. The City of Lawrence and the Bowersock Mills & Power Company entered into an agreement in 1977 that calls for the City of Lawrence to provide limited maintenance activities at Bowersock Dam. The agreement provides that so long as Bowersock operates the power plant and generates a minimum of 1,000 kilowatts per hour of electricity, the City will provide the necessary materials for the maintenance and raising of the Dam flashboards, spillway gates and headgates. Bowersock is obligated to provide all labor and services required to properly maintain or replace the Dam flashboards, headgates and spillway gates. The City has the right to perform maintenance on the dam as the City deems necessary to maintain a pool for its water supply and/or public recreation. The agreement indicates that the City is under no obligation to perform maintenance on behalf of Bowersock and is not liable to Bowersock for any temporary or permanent loss of power generation due to either failure of the dam or decision by the City to discontinue maintenance of the dam. The agreement provides that if the City elects to discontinue maintenance on the dam, it relinquishes its rights relating to the dam, except for the use of the water supply. The agreement provides that the City’s maintenance obligations under the agreement continue until it provides written notice to Bowersock of its intention to discontinue. Thus, the agreement commits the city to ongoing maintenance of the dam for the purpose of maintaining a water supply pool, but does not specify a standard to which the maintenance is completed.
Since 1977, several maintenance projects have been completed. The most recent of these was substantial modification to the structure in 2000–2001. This $2 million project included the construction of a concrete apron along approximately 500 linear feet of the dam.
Impact of Dam on City’s water intakes
The raw water intakes for the City of Lawrence’s Kaw Water Treatment Plant (WTP) are located approximately 2,700 feet upstream of the Bowersock Dam. The intake structure draws water from the upstream pool created by the Bowersock Dam. The intake structure is designed to divert water at levels as low as the concrete crest of the dam. Recent improvements to the raw water pumping allow the full capacity of the Kaw WTP, 16.5 million gallons per day, to be diverted with the water surface of the pool at the elevation of the concrete crest of the dam.
In the event of a failure of the dam or other situation where the upstream pool is lowered or does not exist the Department of Utilities has emergency plans and equipment that would allow the diversion and pumping of raw water to the Kaw WTP. In addition the City is served by a second water treatment plant, the Clinton WTP, which utilizes the Clinton Reservoir as its source of raw water.
Impact of Dam/community aspect and other aspects
There are other reasons that the dam is important to the City of Lawrence. The mill pond, the pool created above the dam, is important aesthetically and provides appropriate conditions for the KU Crew Team and newly constructed boathouse. The dam may be important for the integrity of the Massachusetts and Vermont Street bridge piers. Additionally, the Kansas Department of Transportation has indicated (see attached letter) that it is important for the structural integrity of other transportation infrastructure. There may be other possible stakeholders.
Maintenance Project
In January 2008, the Department of Utilities initiated a repair project as recommended in the February 2007 Black & Veatch report. The project addresses Black & Veatch’s short-term repair recommendations and the scope of work is directed at mitigating flow through the dam, repairing eroded areas on the downstream face of the dam and measures to seal voids on the downstream face of the dam that are not yet leaking. Individual work items include preparatory work to minimize flow through, grout injection into the dam to seal off leaking voides, concrete repairs to eroded areas and additional voids, and shotcrete repair to the downstream face of the dam. The current scope of work is designed to address areas of active deterioration; ie flow through the structure, eroding surfaces, addressing voids that are not yet leaking, and stabilize the dam to provide a window to perform the proposed structural and economic evaluations prior to the discussion of the longer term repair options identified in the Black & Veatch report. This project was proposed to be carried out by coordinating low flow conditions on the river with the construction period and was identified in the City’s 2008 capital improvement program at a total budget of $1,170,000.
During the construction permitting process various state agencies, the US Army Corps of Engineers and FERC reviewed and commented on the proposed project. Questions were raised by FERC regarding the structural stability of the dam and the impact of the proposed repairs on the stability. Due to unknowns regarding the design, construction, materials, foundation and ongoing degradation of the dam Black & Veatch is not able to provide the requested analysis. After further discussion, FERC provided a conditional approval for the proposed repairs based on waiting for flow conditions. In the interim, a window of lower flows allowed for a visual inspection of the downstream face of the dam on January 23, 2009. This was attended by staff from FERC, Bowersock, and Black & Veatch. Based on the conditions observed during this visual inspection Black & Veatch recommends proceeding with the currently proposed repair project, and submitted a letter outlining this recommendation. City utility staff concur with this recommendation to proceed with the current maintenance project.
Subsequent to the recent visual inspection, Bowersock Mills & Power Company received a letter from FERC requesting that dam flashboards be lowered and the mill pond maintained at the level of the dam crest until the maintenance project was completed. This created an immediate impact on Bowersock Mills & Power Company and a desire to accomplish the pending city maintenance project at the earliest opportunity. Over the past several weeks, City staff has worked with Bowersock officials, other regulatory officials, Black & Veatch and the maintenance project contractor, L.G. Barcus, to identify ways the maintenance project could proceed as expeditiously as possible, particularly ways that the project could proceed without reliance on low river flows, perhaps through the construction of a coffer dam (a watertight upstream enclosure that would enable activities to occur in dry conditions and diverts water away from the project area).
It is important to note that the City has already incurred costs related to the maintenance project. These costs include design and permitting fees as well as internal staff time. While the City has not yet executed a contract for the construction, L.G. Barcus the contractor selected based on their response to the Request for Qualifications, has spent considerable time evaluating and estimating repair strategies, and responding to the City’s desire to modify the project in response to Bowersock Mills & Power Company’s request to perform the work utilizing a cofferdam.
Request for larger maintenance project to commence in August
On February 13, 2009, the City received a letter from Bowersock Mills & Power Company requesting that the City consider the delay of the maintenance project that is nearing construction in favor of a larger project which would include selected scopes of work from those proposed in the Long Term Repairs identified by Black & Veatch’s report. They would like to see such a project proceed in August of this year. Bowersock Mills & Power Company has requested the study session for the City Commission to contemplate this request.
In its 2007 report, Black & Veatch prioritized possible long-term repair and improvement areas to be monitored on a routine basis and repaired, as needed, to avoid the development of more critical problems. The repair areas include the sealing of the upstream face of the dam to eliminate flow through and the completion of the sheet piling and apron on the downstream side of the dam Other operational enhancements aimed at extending the life of the existing structure include automation of the spillway gates, construction of downstream nappe and energy dissipaters and the replacement of the wooden flashboards with pneumatic flashboards similar to the existing Obermeyer section. The total rough estimate in the Black and Veatch report of all long-term repair projects was approximately $18 million. While these possible projects are identified in the report, any recommendation to carry them out is prefaced by the need to perform additional investigation into the viability of the existing dam to sustain these improvements long term and the economics of making the long term improvements in conjunction with the continued maintenance cycles on the remaining existing structure. The potential impact of the proposed long-term repairs on the Department of Utilities budget and rates has not been evaluated.
Possible Options to Meet City Responsibilities
There appear to be several potential options for the City to meet its responsibilities regarding maintenance of the dam. Options, with discussion of each, are listed below in no particular order:
Comments: There is concern at this point in time that if given the direction to proceed with the current scope of work, the prospects for completing the project this spring without significant efforts to control flows at the project site are dwindling based on historical river flows and precipitation from now into summer. The execution of the current project will likely be out into August/September based on historical river flows.
Comments: Assuming that this project would be undertaken under the City’s existing procurement policies and procedures, the project would require issuance of a Request for Proposals for engineering services, negotiation of a design contract, design of a project, bidding, contract for construction, permitting, etc. In addition to the time constraints noted above the ability to design a project beyond the short-term repairs is limited by the unknowns surrounding the construction and condition of the existing structure. Black and Veatch identified this in the 2007 report, stating “prior to implementing any of the long term items, additional studies should be performed.” The design and permitting of the proposed long-term repairs will require the ability to obtain, if possible, additional information on the condition and stability of the existing structure. Additional assessment of the dam will require its own low flow window to allow access to the structure for inspection, testing and evaluation.
Even if a scope were known at this point, it would be very difficult to have a construction project ready to commence in August. One option may be to have a more comprehensive investigation and identification of an appropriate scope this fall during low flow periods with a construction project commencing in the winter. Another option would be for the City to suspend its procurement rules and proceed with a design firm that could meet the timeframes involved.
Comments: Under this option, Bowersock Mills and Power Company could have control over the selection of a design consultant and could proceed outside of City procurement and process restrictions. The Bowersock design consultant could present a project to the City to get its participation. If it is desired to meet the August timeframe requested by Bowersock, this may be the most viable alternative.
Funding Options:
There are several potential options for the City to fund a Bowersock project. To specifically be able to inform the City Commission of the impact of any larger-scope project, the scope of such project would need to be more defined so that a potential cost could be identified. These funding options are meant to be general and are listed below in no particular order:
Utilities Master Plan Issues:
City staff believes that in proceeding with the recommended master plan updates for the water and wastewater utilities, Bowersock and other projects can be viewed in the appropriate context.
Conclusion:
Direction from the City Commission regarding how to proceed would be appropriate. The Commission may wish to provide some general direction at this point and request additional information and discussion. Staff is available to provide additional information to the City Commission as desired.