North Coast During the December 26 to January 3 storm period, the
North Coast river basins, despite their lower elevations, received significant precipitation ranging from 10 to 25 inches. The most substantial rainfall occurred in the
Eel and
Russian River basins, leading to severe flooding. The Russian River at
Guerneville reached a flood stage of 45 feet, about 3.5 feet lower than the record 48.56 feet stage in 1986, but still the second-highest stage since 1995. The flooding of the Russian River caused significant damage to farmland and vineyards along the banks of the river including the city of Guerneville. The Merced River at
Happy Isles peaked at 10,100 cubic feet per second during the flood. The snow then began melting during a torrential 24-hour rainfall on January 1–2, 1997. The rain and melted snow overflowed small creeks and eventually the large
Merced River, which flows through Yosemite Valley. Although nearly simultaneous flooding of the Tuolumne River, also originating in Yosemite National Park, did little damage within the park, it did major damage downstream in the
City of Modesto.
Effects The flooding stranded 2,100 visitors in the park. Stranded New Years' vacationers were finally able to begin leaving Yosemite Valley on January 3, as the worst of the flooding was over, though the drive out of the park still saw many cars partially submerged in water. All roads out of the park—
Highway 120,
Highway 41, and
Highway 140—were inundated by the floodwaters. Though there were luckily no human fatalities, Yosemite Valley suffered many damages. Trails and bridges were badly damaged, and about half of all accommodations were destroyed.
Yosemite Lodge, which has its hotel rooms in separate individual buildings, had 189 cabins and 108 hotel rooms badly damaged or destroyed in the flooding, drastically depleting the hotel's capacity. Half of all campsites were destroyed. Trash cans, picnic tables, bearproof storage boxes, and fire grates floated down the river. The estimated cost of rebuilding the Upper Pines, Lower Pines, and North Pines and removing the damaged Upper and Lower River campgrounds was over $8 million. Total park damages were estimated at $178 million.
Highway 120 west out of the park was inundated in many areas and closed for nearly half a year for repairs. Damage assessment was delayed considerably due to a cold front and subsequent snowstorm that brought frozen precipitation back to the Valley on January 5.
Central Valley and Sierra Nevada During the event, runoff from the Sierra Nevada basins that drain into the Central Valley was significantly increased by rain at higher elevations and melting snow. The New Year's Day storm tested the
Sacramento-Feather River flood control system, which had to manage local runoff and reservoir releases to maintain its integrity. Prior to the major storms, reservoirs were able to reduce storage and regain flood reservation space based on forecasts and operations. However, the intense storms around New Year's Day quickly filled these reservoirs near capacity, necessitating increased downstream releases and setting new peak flow records into
Lake Shasta and
Lake Oroville. For the first time, the
Don Pedro Reservoir reached maximum capacity forcing releases with high flows downstream. As a result, the
Tuolumne River at
Modesto reached a record stage height of 71.21 feet and a near-record flow of 55,800 cfs on January 4. The record flows on the river caused considerable flooding to farmland and housing along the river and some neighborhoods in Modesto. The
Dry Creek flooded neighborhoods near the Creekside Golf Course.
San Joaquin River at
Vernalis reached a record peak stage height of 34.88 feet and a near-record flow of 75,600 cfs on January 5. The San Joaquin flooded many communities along its banks, including substantial damage in
Manteca. The
Sacramento River at Verona reached a near-record stage height of 42.09 feet and a record flow of 102,000 cfs. Consequently, levee breaches on the Sacramento and the flooding of the
Yolo Bypass inundated many acres of farmland. The
Truckee River also had near-record flows with a peak stage height of 13.13 feet and a flow rate of 14,900 cfs at Farad (well above flood stage) which flooded Downtown
Truckee. == Aftermath ==