STILLWATER — Authorities have imposed no-wake restrictions on boaters venturing out onto the St. Croix River.

Because of high water levels, boaters on the St. Croix between Taylors Falls and Prescott, Wis., must go slow to reduce shoreline erosion.

Officials from Wisconsin, Minnesota and the National Park Service will post signs regarding the slow no-wake requirement at all public accesses, and marina operators have been notified.

The rule will remain in effect until the river recedes below the 683-foot level, which is expected to take about a week.

Safety officials point out that high-running rivers often carry debris floating just below the surface that can present significant hazards, so boaters should watch out. And they note that the chilly water temperatures pose a serious risk of hypothermia.