ANCHORAGE, Alaska (AP) — Oil production at Prudhoe Bay was cut to 10 percent of normal output after a power outage, and more weather related problems forced the trans-Alaska oil pipeline to temporarily go offline.The pipeline was down for about 10 hours Tuesday after flooding in Valdez likely knocked out fiber-optic communications at five valves on the pipeline. Crews were dispatched by helicopter to manually operate the valves, allowing operator Alyeska Pipeline Service Co. to restart production. About 800 miles to the north, BP PLC crews worked to restore power to the nation's largest oil field after high winds knocked down power lines early Tuesday. Production fell to about 35,000 barrels Tuesday, a tenth of the 350,000 barrels that were produced Monday in the oil field already hampered by problems. Layers of dust and dirt blown by high winds built up on high-voltage insulators on power lines and the field, causing a short and bringing the entire field down. BP crews worked Tuesday to wash insulators, restore power and ramp up production, but it is unclear how long the work would take. Alyeska spokesman Mike Heatwole said company protocol calls for the pipeline shutdown when valves cannot be closed from long distance. “The valves must be staffed by crews that can manually operate the valves,” Heatwole said. The pipeline was brought back online early Tuesday afternoon after those crews arrived by helicopter, Heatwole said. Flooding and mudslides along the Richardson Highway, which parallels the pipeline and is the only roadway out of Valdez, disrupted vehicle traffic. The Alaska Department of Transportation closed a 65-mile stretch of the highway, starting near Valdez. The highway is expected to be closed for several days. The Weather Service said 6.5 inches of rain fell Sunday and Monday at Valdez. Flooding in Keystone Canyon near Valdez hit three bridges hard and moved one five feet, according to DOT spokeswoman Shannon McCarthy. High water along other roads in Valdez was hampering Alyeska's ability to staff the Valdez Marine Terminal, where oil is loaded onto tankers. The terminal is across Port Valdez from the city and a road leading to it was affected by flooding.