For over 15 years, McMillen has provided an extensive range of engineering, regulatory, and natural resource services for both of Chugach’s existing hydroelectric projects (Eklutna and Cooper Lake) as well as a variety of potential hydroelectric sites across Southeast Alaska, including Snow River, Fourth of July Creek, and Godwin Creek. Sample projects include:
Cooper Lake FERC Relicensing and License Compliance:
McMillen served as the lead consultant for the entire relicensing process. As an early first step, we conducted preliminary outreach efforts with expected relicensing participants and prepared a Relicensing Recommendations Document. These early recommendations provided the basis for Chugach’s decision to select an enhanced Traditional Licensing Process (TLP) for the relicensing. In addition to preparing all relicensing documents, McMillen assisted with specific study efforts. We conducted a preliminary fish entrainment risk assessment, provided consultation assistance for an instream flow technical workgroup, and managed consultation with Alaska Native organizations and other parties for Section 106 consultation on cultural resources. We also assisted Chugach with strategic planning and implementation of negotiations that culminated in a multi-party settlement agreement for the project. FERC issued a 50-year license for the Cooper Lake project in August 2007. Since then, McMillen has supported Chugach in meeting its compliance requirements under the new license. Our ongoing assistance ensures that Chugach remains in full compliance with regulatory obligations and environmental standards.
Eklutna Fish & Wildlife Agreement Implementation and Design Services:
The Eklutna Hydroelectric project does not have a FERC license, but instead must comply with a unique Fish and Wildlife Agreement that was executed with the U.S. Fish and Wildlife Service, National Marine Fisheries Servies, and the State of Alaska. McMillen is the lead regulatory, natural resource, and engineering consultant, managing the ongoing consultation and study process required by the Fish and Wildlife Agreement. This process is very similar to a FERC relicensing process; however, the project owners will receive a Final Fish and Wildlife Program from the Governor instead of a license from FERC. McMillen has developed all documents to date. Additionally, our services include strategic planning and overall project management, stakeholder management, multi-year natural resources study program management, and engineering services. Our design of protection, mitigation, and enhancement (PME) measures will satisfy the intent of the Fish & Wildlife agreement. Component improvements include a dam outlet modification, a river release valve, a dam gate upgrade, and the maintenance of road bridges.
Cooper Lake Dam Safety:
McMillen supports all aspects of FERC dam safety compliance for the Cooper Lake Hydroelectric project. This includes conducting the 2018 Part 12D inspection, updating the Supporting Technical Information Document (STID), preparing the annual Dam Safety Surveillance and Monitoring Reports (DSSMR), and assisting Chugach with meeting all Emergency Action Plan (EAP) requirements. McMillen also updated the seismic hazard assessment of the dam and developed new seismic loads and a design response spectrum for use in a seismic stability analysis. We are using current fault information and ground motion estimation methodologies to update the design ground motions for the area.
Eklutna Dam Safety:
McMillen supports all aspects of state dam safety compliance for the Eklutna Hydroelectric project. McMillen’s dam safety scope of work has included conducting the last two periodic safety inspections (2018 & 2021), spillway condition assessments, inundation modeling, and assisting Chugach with meeting all EAP requirements.
Cooper Lake Siphon Improvements:
McMillen is conducting a comprehensive assessment of the operational constraints of the existing siphon and evaluating potential modifications to improve operational flexibility to meet FERC license requirements. Work includes an alternatives analysis, design of siphon improvements, and license amendment application to reflect practical siphon performance conditions. Additional design services provide remote operation of the Stetson Creek Diversion structure and the siphon and year-round access to the dam and diversion structure.
Eklutna Adit Tunnel Rehabilitation Design-Build:
The Eklutna adit tunnel provides inspection and maintenance access to the main power tunnel. Portions of the 300-foot-long tunnel lining degraded significantly during its lifespan (e.g., timber lagging decay, steel component rust, and scale). McMillen performed a condition assessment, developed a detailed design of the new lining system, replaced the timber lagging with galvanized steel, backfilled voids with concrete, and executed rehab activities.
Hydro Site Evaluations:
McMillen conducted two previous feasibility assessments of new hydroelectric sites for Chugach: 1) Fourth of July / Godwin Creek and 2) Snow River. Field reconnaissance was performed for both sites to identify potential dam/intake locations, penstock/tunnel alignments, powerhouse locations, construction access, and transmission line routing. We conducted a preliminary environmental assessment, identified land ownership, developed a preliminary permit application and water right application, conducted a preliminary hydrology investigation, developed energy generation models, and outlined a construction approach. In 2022, Chugach requested our support in progressing the development of both projects via stream gaging, development of a Renewable Energy Fund (REF) grant application, and coordination of water rights. This work is being conducted as part of a broader decarbonization program that will look at additional potential hydroelectric sites across Southeast Alaska.
