A torrent of rain battered West Marin last week, washing out roads, triggering mudslides and causing flash floods. After four days of steady downpours, the brunt of the storm arrived on Tuesday, as an atmospheric river—a narrow band of moisture propelled by powerful winds—swept across the region. The National Weather Service recorded nearly five inches of rainfall in Point Reyes Station over a 24-hour period, on top of the 4-plus inches that had fallen earlier in the week. “The west-facing coastal ranges outperformed what we had forecasted,” said Joe Merchant, a meteorologist with the weather service, which initially predicted roughly half that total. Before dawn last Tuesday, creeks in West Marin had overflowed their banks, inundating roads and stranding drivers. The Marin County Fire Department responded to seven water-rescue calls, according to spokeswoman Mari Ochoa. “A question that often comes up is how we define a major storm,” she said. “In my experience, anything more than 3 inches in 24 hours causes significant flooding.” As conditions intensified, fire agencies across the county assembled the Office of Emergency Management’s swift-water rescue unit. They pre-position resources when prolonged, heavy rainfall is forecast and deploy the unit when water-related calls come into emergency dispatch. One rescue occurred just after 5 a.m. on Platform Bridge Road, where a sheriff’s deputy pulled a woman from her car after she hit a large puddle, veered off the road, and landed in a flooded Lagunitas Creek. Trapped inside as water filled the vehicle and her door locks and windows failed, she managed to call 911. Deputy Mike Dawson arrived within minutes. Body-camera footage released by the sheriff’s office shows Deputy Dawson leaping into the floodwaters and using a tool from his duty belt to smash the car’s back windshield. “Can you hear me?” he asked, then reassured her: “I’m right here, okay?” Moments later, he guided her through the opening to safety. “I got you,” he said. Shortly after, the car became completely submerged. “The entire incident lasts just minutes, showing how significant storm activity can be,” the sheriff’s office said in a statement. “We are thankful for the positive outcome during this incident and want to remind everyone to slow down in inclement weather and DO NOT drive through standing water on the road.” Last Thursday, Marin Water had reported 42.77 inches of rain at Lake Lagunitas since July 1 or about 133 percent of average for that period. Last year, another wet year, the figure was 42.94 inches. The district’s seven reservoirs were at 99.95 percent of capacity last week. West Marin is expecting another storm today.