SONOMA COUNTY, CA — Four Sonoma County creeks and the Russian River reached flood stage and one creek was nearing flood stage during the current rainstorm, according to the National Weather Service San Francisco Bay Area and the California Nevada River Forecast Center.
A flood warning was in effect Tuesday for Santa Rosa, Rohnert Park, Sebastopol, Cotati, South Santa Rosa, Forestville and Graton as small-stream flooding caused by excessive rainfall continued.
A flood watch was expected to remain in effect for the North Bay until Wednesday morning.
Find out what's happening in Healdsburgwith free, real-time updates from Patch.
Mark West Creek
Mark West Creek at Mirabel Heights reached minor flood stage — 55 feet— Monday and its waters continued to rise Tuesday. As of 5:45 p.m., the creek reached 58.61 feet with the moderate flood stage set at 59 feet.
According to flood impact scenarios provided by the National Weather Service, when the water reaches the moderate stage, Trenton-Healdsburg Road begins to flood at the lowest spots on the right bank (north side). Portions of Wohler Road downstream also likely flood, including the Wohler Road Bridge over Mark West Creek. NWS usually issues a flash flood warning if not already issued.
Find out what's happening in Healdsburgwith free, real-time updates from Patch.
The predictions were correct Tuesday; a car reportedly became stranded Tuesday in the floodwaters at the Wohler Bridge, the California Highway Patrol said.
If the creek reaches the major flood stage —65 feet — there is major roadway inundation on Trenton-Healdburg Road, Wohler Road in the vicinity of Mark West Creek, and Eastside Road. Trenton-Healdsburg Road bridge over Mark West Creek is flooded and/or backwatered. There is also major flooding — 5-10 feet of water — in the lowest vineyards adjacent to the channels. Lower Windsor Creek also likely floods.
Click Here: offaly gaa jerseys
Green Valley Creek
Green Valley Creek at Martinelli Road reached minor flood stage — 59.9 feet — Saturday. Its waters surpassed the moderate flood stage Monday morning and reached 63.35 feet late Monday. At 7:15 p.m. Tuesday, the latest observation showed the creek was at 62.23 feet.
According to flood impact scenarios provided by the National Weather Service, when the creek reaches the minor flood stage, water begins to inundate the floodplain along Green Valley Creek near the Martinelli Bridge and gaging site. Local property access may be compromised.
When it reaches the moderate flood stage, local property access driveways and bridge crossings begin to flood and backwater — some by several feet. Access to, or egress from, local floodplain properties becomes dangerous or impossible.
If the creek reaches the major flood stage, water levels are backwatering the Martinelli Road Bridge and possibly spilling over the roadway. There is major regional flooding on Green Valley Creek and other local creeks. Local residential access roads to creekside properties become underwater by several to many feet. Local bridge crossings become impassable. Martinelli Road is likely flooded and travel becomes difficult to impossible.
Russian River
The Russian River at Digger Bend near Healdsburg was at 23.36 feet at 7:15 p.m. Tuesday, down from 24.37 feet. The minor flood stage is 25.4 feet.
According to flood impact scenarios provided by the National Weather Service, when the Russian River at Digger Bend reaches the minor flood stage, the lowest floodplain roads on either side of the river are inundated. The weather service usually issues an urban/small stream advisory if not yet already issued. When the river reaches the moderate flood stage of 25.4 feet, there is moderate flooding on the right bank (west side) levee and the Healdsburg well field foundations become inundated. The NWS will issue a flash flood warning if not yet already issued.
If the river reaches the major flood stage, the left bank (east side) point bar becomes completely submerged. The city of Healdsburg well field heads and highest point bar roadbeds become at or below water level. The adjacent floodplain becomes inundated on both sides of the river and private residences nearby are threatened by floodwater if not already flooded.
Santa Rosa Creek
Santa Rosa Creek at Willowside Road near Santa Rosa was at 66.98 feet at 7:15 p.m. Tuesday, down from 69 feet Monday. The creek’s minor flood stage is 70 feet, which it surpassed Sunday night when it rose to 70.67 feet before falling back below flood stage Monday.
According to flood impact scenarios provided by the National Weather Service, when the creek reaches minor flooding, Ewok Trail begins to flood. NWS will issue an urban/small stream advisory, if not yet already issued.
When it reaches the moderate flood stage, water levels reach the underside of the bridge deck at Willowside Road. Further rising of water levels will cause backwater effects at the bridge with waters seeking alternative routes around the bridge — with possible build up and overflow of roadway. NWS will issue a flash flood warning, if not yet already issued.
During major flooding, Willowside Road becomes inundated and many feet of water cover adjacent vineyards.
Colgan Creek
Colgan Creek near Sebastopol surpassed minor flood stage — 75 feet — Saturday and reached 77.03 feet Sunday which put it into moderate flood stage— 76.5 feet— Sunday. As of 8:15 p.m. Tuesday, waters were continuing to recede below minor flood stage with the creek at 74.46 feet.
According to flood impact scenarios provided by the National Weather Service, when this creek reaches the minor flooding stage, the floodplain upstream of the Llano Road bridge on the bank (north side) begins to flood into the adjacent farmland. NWS issues an urban/small stream advisory, if not yet already issued.
When it reaches the moderate flood stage, there is additional floodplain and roadway inundation on Llano Road. NWS issues a flash flood warning, if not yet already issued.
If it reaches the major flood stage, there is major floodplain inundation and water levels rise approximately 1 foot above the elevation of the bridge deck on Llano Road.
East Washington Creek
East Washington Creek at Garfield Drive in Petaluma on Saturday surpassed the minor flood stage — 66 feet— when it reached 66.53 feet. The water was at 64.18 feet at 5 p.m. Tuesday and was continuing to fall.
The National Weather Service did not provide flood impact scenarios for this creek.
Get more local news delivered straight to your inbox. Sign up for free Patch newsletters and alerts.