Drilling Crews Continue Work After Fracture Found at Wanapum Dam - NBC Right Now/KNDO/KNDU Tri-Cities, Yakima, WA |

Drilling Crews Continue Work After Fracture Found at Wanapum Dam

Posted: Updated:
Drilling work is continuing at Wanapum Dam as crews continue to examine a 65-foot fracture found in a spillway pier in February. Drilling work is continuing at Wanapum Dam as crews continue to examine a 65-foot fracture found in a spillway pier in February.
Drilling work is continuing at Wanapum Dam as crews continue to examine a 65-foot fracture found in a spillway pier in February. Drilling work is continuing at Wanapum Dam as crews continue to examine a 65-foot fracture found in a spillway pier in February.

GRANT COUNTY, WA - Drilling work is continuing at Wanapum Dam as crews continue to examine a 65-foot fracture found in a spillway pier in February.

A drilling team has so far completed six investigative holes into the dam's spillway pier monolith No. 4. Drilling will resume after crews construct a larger platform on the monolith to support the workers and their equipment.

Windy weather has caused some delays in the drilling process. All work on the monolith must stop in wind gusts that are more than 35 miles per hour. The platform construction and drilling should take about three to four weeks without significant wind delays.

The drilling will help determine the geometry of the fracture and how far it reaches into the monolith.

Grant PUD is also working to modify the fish ladders at the dam. Workers are currently installing pumps in the dam's two fish ladders and will install weirs and flumes to help migrating fish navigate to the top of the ladders and then to the reservoir behind the dam.

Grant PUD lowered the Wanapum reservoir in elevation by 26 feet to stabilize spillway pier monolith No. 4. This action made the fish ladders inoperable without the modifications.

Work on the fish ladders is expected to be completed by April 15, which is the start of the spring Chinook salmon run.

Grant PUD has accelerated plans for boat launch improvements during the reservoir drawdown, which decreases cost and environmental impacts by doing work in the dry. New estimates show that the utility will save nearly $1 million for improvements to the Kittitas Boat Launch and Frenchman Coulee recreation sites near Vantage after competitive bids were submitted last week.

The Wanapum shoreline remains closed during the low-reservoir conditions because of safety hazards and to protect culturally sensitive sites.

HD DOPPLER 6i
/