MINA, S.D. — Three months after damage was discovered at the Mina Lake spillway, South Dakota Department of Game Fish and Parks officials have determined it is significant and repairs are needed.

That comes after an inspection of the structure. The extent of repairs is yet to be determined.

Initial damage was found March 31 when a piece of the spillway was spotted at its base. With the high volume of water running across the spillway at the time, officials weren't certain where the piece came from.

Water from Mina Lake goes over the spillway into Snake Creek at the southeast corner of the lake, which is about 10 miles west of Aberdeen.

GFP Program Administrator Al Nedved said Banner Engineering recently evaluated the spillway and noted considerable damage.

The preliminary cost estimate to replace the dam is $1.8 million, Nedved said, and that's to rebuild the structure as it is today.

Nedved said when heavy flows of water entered a lower section of the spillway, it lifted and moved a piece of concrete.

The dam has been in place since 1934.