Middle Dam Construction Updates

 

About the Middle Dam Project

As the owner of Middle Dam, Brookfield White Pine Hydro, LLC is required to meet certain dam safety criteria mandated by the Federal Energy Regulatory Commission’s (FERC) license issued in 2002 to operate and maintain the facility. Middle Dam is a circa 1850s dam that has undergone numerous repair and upgrade efforts during its lifetime. The facility must undergo future repairs to meet FERC dam safety requirements. After evaluating both replacement and in-kind repair options, Brookfield White Pine Hydro, LLC, has determined to pursue a repair, which will minimize stakeholder and environmental impacts. Continued detailed on-site inspections, consultation, and coordination with FERC engineers, and an Independent Engineer, along with ongoing discussions with stakeholders have resulted in making this determination. Specifically, the repair project will meet the dam safety criteria of accommodating Inflow Design Flood (IDF). We do not anticipate significant impacts to recreational and fishing access, or aquatic habitat with the repair option. The piers, aquatic habitat, and access to the pool are expected to remain as is following the repair efforts.

The items below feature the latest construction updates.

Middle Dam Construction Update 

June 16, 2021 – Pier 3 and Pier 1 have been open since May 23 with new handrails and grating installed. The remaining work for the Middle Dam repair project for this summer includes:

  • Road maintenance.
  • Lower and upper laydown area construction.
  • Installation of the angler access trail.

This work is scheduled to start August 2 and is expected to conclude before Labor Day.

Middle Dam Construction & Road Update 

May 11, 2021 – Pier 3 has been accessible since April, while Pier 1 experienced some delays due to typical spring access issues, however, it is expected to be open by May 23.  The remaining work for the Middle Dam repair project for this summer includes:

  • Road maintenance.
  • Lower and upper laydown area construction.
  • Installation of the angler access trail.

This work is expected to conclude in July.

As a courtesy notification, Seven Islands is making repairs to Fish Pond Road, including a bridge replacement. Seven Islands will limit access from May 24 to May 28. Please note, these repairs are entirely independent of Brookfield Renewable operations.

More information on the Richardson Lake and Androscoggin watershed conditions will be forthcoming pending expanding drought conditions.

Thanks to all parties that we share the roadways with while we safely complete these projects before summer recreation season.

Pier Construction & Access Update 

April 2021 – As part of the winter 2021 construction, Pier 1 and Pier 3 are undergoing repairs.  Pier 3 repairs are complete and  Pier 3 is now accessible.   Pier 1 repairs are underway with completion expected in May and once complete, access will be fully restored.

 These photos, taken in late March, depict Pier 3 repairs.  Pier 3 repairs are fully complete.  

2021 Newsletter 

Click here to view the 2021 newsletter update for Richardson Lake stakeholders.

 

Winter 2021 Construction Update 

January 2021 – We expect to start the railing system installation efforts in February, with targeted completion by the end of April, to ensure access is fully restored before recreation season.  Specifically, the guardrail design on piers #1 and #3 will meet the International Building Code (IBC) standards. The rails around the fishing platform and platform deck have been designed and fabricated to accommodate public safety and the gentle catch and release of fish.  In addition to the walkway and railing repairs, and as part of our winter work plan, we’ll be replacing deep gate #4.  We will construct the laydown areas and the angler trail through the summer and fall months, which will conclude our planned work for 2021.

Summer 2020 Construction Update

July 2020 – Starting this month, the second phase of work for 2020 will start at Middle Dam and the work is expected to conclude in early October.

In July, workers will replace the gatehouse floor and grate with much of the work taking place in the gatehouse’s interior.   Installation of the deep gates will occur on the weekends of July 17, July 24, July 31, and August 7.  Scheduled white water releases may be extended by 12 to 24 hours to accommodate the repairs.  Deep gate repair work will occur on 24-hour shifts with minimal light and noise impacts. All final components of the deep gate repair project will conclude in early August.

Steel plating, which will attach to the upstream walls of piers #4 and #5, will be installed in early August through late September.  In parallel, other tasks will also take place that includes realigning and replacing any missing concrete logs on piers 2 and 4, replacing the gatehouse floor, and changing out the existing box tubes on Pier 4.  The final component of work, removing plating and conducting structural work on the downstream side of Pier #2, will occur from mid-September through early October.  All work is expected to conclude by the second week of October.

With the exception of the deep gate installation, the work will take place during daylight hours on Monday through Friday.   During the deep gate replacement and steel plate installation, there may be slight delays on the bridge to accommodate workers’ safe passage and movement of equipment.  No significant recreational impacts are anticipated through the duration of work, and contract monitors will be on-site to help ensure public safety.

Should there be any significant changes to the current maintenance timeline or scope, stakeholders will be notified accordingly. Brookfield Renewable will continue to update this website to keep stakeholders apprised of the activities and schedule.

Planned Repair Schedule for Middle Dam 

*Please note, this schedule is subject to change pending FERC approval. Regular construction and recreation updates will be shared regarding the various phases of this project. 

Year 1 Project Schedule

This photo diagram shows the various repair components for Middle Dam.

Late winter through spring, 2020

  • Pier repairs
  • Replace Shoal Gates

 

Summer through late fall, 2020

  • Pier repairs
  • Replace Deep Gates
  • Rebuild gatehouse floor, structure
  • Construction laydown areas & angler trail

 

Year 2 Project Schedule

Late winter through spring, 2021

  • Pier inspections 4/5
  • Replace Deep Gate 4
  • Walkway replacement on Piers #1 and #3

 

Summer through fall, 2021

  • Construction laydown areas and  angler trail

 

Year 3 Project  Schedule*

Winter through spring, 2022

  • North spillway structural rehabilitation
  • Shoal gate area structural rehabilitation
  • Pier rehabilitation (5,6)

 

Summer through fall, 2022

  • Deep gate area structural rehabilitation
  • North spillway crane pad installation

 

Year 4 Project Schedule*

Winter through spring, 2023

  • Sluice gate area structural rehabilitation
  • Pier rehabilitation (1,2,3,4)
  • South spillway structural rehabilitation 

 

Summer through fall, 2023

  • Pier rehabilitation (4,5)
  • South spillway crane pad installation
  • Bridge rehabilitation
  • South Spillway gate/structure rehabilitation

 

Year 5 Project Schedule*  

Winter through fall, 2024

  • Deep gate area structural rehabilitation

 

Summer through fall, 2024

  • Install remaining fishing access, walkways, & handrails
  • Site restoration

 

Winter 2020 Update

The latest update from Brookfield Renewable includes recent developments with permitting for the Middle Dam Repair Project as well as provide an overview of necessary maintenance work scheduled for 2020.

As previously stated, the change from a reconstruction project to a repair of the existing structure significantly minimizes the scope of work and impacts on the environment and local stakeholders. With the material change expected to result in fewer permit requirements, Brookfield Renewable will be withdrawing its HP30 permit with the Maine Land Use Planning Commission (LUPC). On December 19, Brookfield White Pine Hydro, LLC, filed a letter with the LUPC to notify the agency of the intent to withdraw and refile a new application. A copy of this letter is available on the Documents section of this webpage. A new permit application for the reduced scope of work, mainly pertaining to temporary staging areas will be submitted in early 2020.

In the meantime, minor maintenance activities will take place starting in February through April at Middle Dam. The scope of maintenance work includes rebuilding the gatehouse floors and installing new gates of the same size. This maintenance work will not change the footprint of the existing structure, nor will it alter the overall aesthetics of the facility.

Some of the maintenance work is expected to take place seven days a week and after dusk; however, the timing will vary throughout the duration of this project phase. Due to weather conditions, this timeline is subject to change. During the 2020 maintenance work, vehicle and snowmobile crossing and foot traffic at the dam bridge may be limited for safety purposes, and delays may occasionally occur.

Should there be any significant changes to the current maintenance timeline or scope, stakeholders will be notified accordingly. Brookfield Renewable will continue to update this website to keep stakeholders apprised of the activities and schedule.

 

Fall 2019 Update 

In recent months, representatives from Brookfield Renewable’s Northeast operations held meetings with the Federal Energy Regulatory Commission and the Maine Land Use Planning Commission on the consultation and review of the Middle Dam repair project.

The change in approach from a reconstruction project to a repair project has resulted in a repair in-kind with the same footprint, thus minimizing impacts on the environment and mitigating recreation and stakeholder concerns.

Specifically, the highlights associated with the overall Middle Dam project include no anticipated changes to the tailrace, piers and handrail heights, and the overall aesthetics of the gatehouse structure.  With the repairs being made in-kind, there will be no development of a bypass channel or cofferdams.  We do not expect any work to occur in the wet and subsequently, we anticipate no major drawdowns outside of normal operations.  Minor maintenance work to the gate structure is scheduled for this winter.

With this change in approach, fishing access at the dam will be available throughout the duration of this project. Due to safety concerns, fishing access may be temporarily limited to a single pier at a time.  We also expect to repair the piers and restore access to the pier that is currently closed allowing for increased fishing access over the existing conditions.   The pier handrails and railings will also be improved for safer use.   Maintenance work for the piers is scheduled for this winter.