Delhi Dam Construction Progress Report #4
July 8, 2014
General Project Information
As has been discussed, Phase 1 was awarded to Lunda Construction Company, a large and experienced heavy structural midwest firm from Wisconsin in April 2014.
The DNR permit allowing the entire project to be constructed including Phase 2 has been received clearing the way to complete the project.
The important critical goal of Phase 1 work is to complete enough refurbishing work on the concrete structure to allow river water flow to be diverted from the current river bed through the concrete structure.
The timing of the Phase 2 bidding depends on being confident that Phase 1 work will be substantially complete by October 2014 allowing for the river to be diverted through the refurbished concrete structure. Right now in looks like Phase 2 work will be bid in July 2014 for an August 2014 contract mobilization to begin this work.
Project completion date is dependent on several factors including river flows being average or below, few weather extremes in the next 12 months, selecting a quality contractor for Phase 2 equivalent to our Phase 1 contractor and finally that the flow in the river at the time needed to refill the lake is sufficient.
Right now, again for planning purposes, we are planning for a July 4, 2015, date to resume enjoyment of Lake Delhi. It could be ready sooner if everything listed above goes great.
Specific Progress by Lunda on Phase 1 work through July 8, 2014 includes:
River flows are returning to more normal summer flows although they are still higher than average. This high river flow has slowed work on the project due to flooding of the upstream and downstream cofferdam areas. Temperatures have been from the 60’s to the mid 80‘s. Several rain events have also slowed progress.
The upstream cofferdam had to be strengthened following the high water event of the last week or so to reduce leakage to a tolerable amount.
Lunda has had to use Swamp Mats to bridge the mud on the upstream side of the dam so a track hoe could access the SW corner of the dam to set sheet piling in the existing upstream cofferdam to stop water from leaking into the Rock Anchor excavation.
Following driving sheet pile at this location, Lunda is drilling a grout curtain to stop water from entering the excavation hopefully allowing the area to be made ready to resume work on the rock bolting requirements for Phase 1.
Concrete sawing has continued on existing pier noses for their removal. Lunda has removed the top 6.5 ft. of the north pier nose and hauled it to the farm up X31 at the top of the hill.
Work Progress from June 20, 2014, to July 8, 2014
Excavation for the Rock Anchor Block is 90% complete and on hold until the area can be dewatered.
Lunda has finished assembling scaffolding and placing it on top of spillways for pier nose removal.
Eastern Iowa Concrete Sawing has been sawing on existing pier noses for removal.
B&J will continue pumping ground water from stilling basin.
Downstream Silt removal required for inspection is complete.
Finally, Lunda is constantly moving equipment and material to and from the site from their headquarters in Little Shute, WI, as needed due to the tight working conditions on the north side on the dam w here Phase 1 work is happening. Below the large track hoe shown above left the site today as it’s work is done for now. Sightseers are doing a good job of staying away from this work area and it is appreciated by the project.
Next Dam Construction Report – Thursday, July 24, 2014
Pat Colgan