PROJECT ALERT NOTICE (CA) Flooding expected for CA this week as ARs bring more rain - Day 4

Date: Fri, 10 Feb 2017 16:24:05 EST

Summary: Flooding is expected this week as multiple atmospheric rivers bring rainfall and snow to parts of California.

A series of warm storm systems are expected to bring precipitation to parts of California through next week. Today, much of central and northern California will experience light to moderate rainfall, with precipitation tapering off tonight and tomorrow. Many counties remain under flood warning or flash flood watch. Caltrans reports numerous road closures due to slides, flooding, and wash-outs, causing access challenges for some USGS crews.

Currently, 61 percent of USGS streamgages in CA are reporting streamflows more than 90 percent above normal flow for this time of year. The NOAA/NWS California Nevada River Forecast Center reports many California rivers currently exceed flood (22 sites) or monitor (27 sites) stage, with peak flows expected today.

The USGS California Water Science Center (CAWSC) has 19 crews responding to this event today from the following service areas: Redding, CA (2); Ukiah, CA (4); Truckee, CA (3); Sacramento, CA (5); Santa Cruz, CA (3); and Santa Maria, CA (2). Crews are performing high-water measurements, flagging high-water marks, and making repairs. Data quality or transmission issues have been identified for at least five stations since this storm system began. Questionable data have either been removed from NWISWeb or warning statements have been added to qualify the data.

USGS Crews are also out today measuring discharge and collecting sediment samples for the USGS Cache Creek Settling Basin Project, a study that examines sediment and mercury loads into and out of the Cache Creek Settling Basin with larger implications for water supply, flood management, water-quality, and ecological health.

CAWSC staff remain in contact with water-resource managers and cooperative partners to communicate and coordinate USGS flood-response work. No safety issues have occurred during this series of storms and all staff have followed USGS field reporting and safety protocols. Several crews are expected to deploy tomorrow for recessional measurements. Updates will continue to be provided during the course of this event.