BEVERLY - A drilling team has completed six investigative holes into the Wanapum Dam spillway pier monolith No. 4 as part of the forensic examination of a fracture found in the structure on Feb. 27.

Windy weather has created delays in the drilling process, according to Public Information Officer Thomas Stredwick. All work on the monolith, which is only accessible by boat or crane, must stop in wind gusts that are more than 35 miles per hour.

Drilling will resume after a larger platform is constructed on the monolith to support the workers and their equipment. The platform construction and drilling is expected to be done this week, barring significant wind delays. The drilling will help determine the geometry of the fracture and how far it reaches into the monolith.

On another front, Grant PUD is on track with modifications to the fish ladders. Workers were 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.

However, Grant PUD plans to trap fish at Priest Rapids Dam and haul them in trucks to Wanapum or Rock Island dams during the first few weeks of the fish run while the effectiveness of the ladder modifications is evaluated.