Math error blamed for Wanapum Dam crack

Math error blamed for Wanapum Dam crack
This undated photo provided by Grant County (Wash.) public utility, the Wanapum Dam on the Columbia River, Wash., is shown. (AP Photo/Grant County (Wash.) public utility)
SPOKANE, Wash. (AP) -- The preliminary results of what caused a big crack in Wanapum Dam point to a mathematical error during design of the structure more than 50 years ago.

That's according to the Grant County Public Utility District on Tuesday.

The crack formed across a spillway of the huge dam, and may have been exacerbated by a weak construction joint.

The preliminary findings will be submitted to the utility's Board of Consultants for final review.

The utility says a team of engineers discovered the mathematical error while examining the original design calculations of the Wanapum Dam spillway. When they recalculated the design formulas, they found that additional concrete and/or reinforced steel should have been used in the construction.