With flash flooding on the east side of Mason Valley, the Mosquito Abatement District will be treating a wide area with an aerial larvacide. They say it’s vital to start treating those waters before the larvae begin developing into biting mosquitoes, creating a public health threat. As for the flooding, as many as 150 homes are impacted in Mason Valley with water in streets and yards,  about ten miles east of Yerington. Apparently no evacuations were needed.