Lake Placid Dam September Project Summary

Date of Report: September 13, 2024

Recent Activities:

Since the last Report on August 11, 2024, all of the Bay 1 spillway slabs have been completed. In addition, the infill concrete inside the center pier void was completed. The center pier fishway concrete extension was completed. Muscle relocation and exploratory excavation for Bay 2 was completed. Structural concrete work for the center pier and north abutment wall was started. South embankment grading, utilities, and grade beams for dam armoring have continued.

Change Orders:

1. Change Order: The existing concrete substructure had unexpected voids that required grouting. Sundt drilled several holes into the existing concrete substructure and filled the voids with grout to ensure the existing structure(s) would adequately support the new concrete structure poured on top of the existing substructure. A unit cost was agreed upon and a change order is being processed for this additional work.
2. Change Order: Lake Placid switchgear replacement. More information will be provided once Sundt obtains pricing from their subcontractor. [“Switchgear” is a broad term that describes a variety of switching devices that address controlling, protecting, and isolating power systems, and include devices to regulate and meter power systems and technology.]
3. Potential Change Order: While excavating for dam armoring on the south side of the project, a Springs Hill Water Supply water line was damaged. The water line appears to be abandoned, but Sundt, Black and Veatch, and GBRA are still talking with Springs Hill Water Supply to determine the remedy.

Schedule:

As mentioned in the August Project Summary, Sundt has implemented various ideas to recapture time lost through the change orders to date (e.g. delays caused by unanticipated debris discovered upstream of Bay 1):

1. Sundt, as promised, has added an additional crew to work on both the McQueeney dam and Lake Placid dam. The extra crew has been switching between the McQueeney and Placid sites and has worked from 8 pm to 6 am. Sundt intends on adding more men to this night crew, so that both sites can have their own dedicated night crew.
2. As previously mentioned, when Sundt will be driving piles for the cofferdam in Bay 2, Sundt will be working the crews longer shifts (but again, not during the nighttime hours).
3. Sundt will be cutting off the cofferdam in Bay 1 starting on September 24, 2024. The cofferdam pilings will be cut two (2) feet lower than the elevation of the upstream slab, which is an elevation of 483.33'. Once the contractor begins this process the lake level will be two (2) feet lower than the current elevation, and the lake will remain at that level for the duration of the project.

NOTE: With approved change orders to date, the Substantial Completion date for Lake Placid is July 24, 2025, which is forty-two (42) days beyond the Substantial Completion date specified in the Contract. It is important to note that the Substantial Completion date does not take into account the time needed to fill Lake Placid nor the final testing of the gates (as the lake has to be full in order to perform the final testing).

Other Items of Interest:

1. Steel Fab gate manufacturing remains on schedule to meet the needs of Sundt’s construction dates. All four (4) of the quarter sections of the Bay 1 gate have been delivered and are present on site. The first of four (4) quarter sections of the Bay 2 gate is expected to be delivered October 2, 2024.
2. The Hydraulic Cylinders’ fabrication and acceptance testing remains on schedule to meet Sundt’s construction dates.

Upcoming:

In the next several weeks, we expect (1) structural concrete lifts #1 and #2 in the center pier and north abutment wall; (2) cutting of Bay 1 cofferdam sheet pile (see also Item 3 under “Schedule” heading, above); (3) begin driving and installation of sheet pile for Bay 2 cofferdam; and (4) continued south embankment dam armoring earthwork and concrete placements.

Updated Substantial Completion Date: July 24, 2025

Recent Photographs of Construction Activity/Progress —