May 11, 2007
Touchstone Energy® Cooperatives in eastern South Dakota continue to make repairs following a severe storm that spawned tornadoes and heavy rains during the weekend of May 4-6. The overload of precipitation -- up to 10 inches in some places -- led to flooding, which threatened transmission facilities later in the week.
A tornado damaged several sections of East River’s high-voltage transmission lines in eastern South Dakota on May 5. The storm path generally followed the James River Valley, from Yankton to Aberdeen, disrupting transmission service in several areas.
East River crews repaired seven broken power poles in the Utica/Tabor/Tyndall area, north of Yankton, from a tornado that struck the area around 6:45 p.m. Saturday. In addition, electric distribution lines of Bon Homme Yankton Electric were also damaged by the severe storm.
Continuing north, the storm also hit an East River Electric transmission line in the Plano area, east of Mitchell, and also near Aberdeen. Two transmission poles were reported destroyed near Plano, which were replaced and new conductor restrung on Sunday. Also, a transmission pole was snapped along the circuit near Aberdeen, which serves FEM Electric Cooperative, and was replaced Sunday.
More than 7,000 cooperative members were without power during the height of the storm. Power was restored to all East River substations by Sunday afternoon. Meanwhile, East River and affected distribution cooperatives continued to make repairs on damaged electric lines.
Following the weekend downpours, rising water threatened several East River facilities. As the James River crested above flood stage, several feet of river water covered the Ferney Substation. The substation, located southwest of the Groton Generating Station, was taken off-line, while Northern Electric crews rerouted power to their members through distribution circuits. East River telecommunications technicians relocated load management equipment higher in the substation building to prevent water damage on May 8.
Flash flooding eroded the ground around an East River transmission pole near the Morningside Substation. Because of the leaning pole on the Morningside Tap, the substation was taken out of service, and Dakota Energy rerouted service through its distribution system. Similar transmission pole erosion occurred along a transmission line near Fedora, in Central Electric’s service area.
South Dakota Gov. Mike Rounds toured the flood-damaged areas, especially hard-hit Aberdeen. The governor ordered into operation the state’s Emergency Control Center to assist communities and utilities with the disaster. The James River was expected to crest at a record six feet above flood stage.