NWS Flood Summary
Hydrologic Information Center
10:45 a.m., EST, Monday January 6, 1997
Flood Summary
Cooler, Drier Conditions Aid Flooding Problems in the West
Dry and cooler conditions during the weekend across the West Coast helped many of the rivers
and streams to return to within their banks. The major exception is the northern San Joaquin
River Valley, where high reservoir releases and continued runoff from the mountains have kept
rivers and streams rising. Major flooding is occurring along the Tuolomne River and the San
Joaquin river below the Friant Dam near Mendota.
Flash Flooding
During the Weekend, Urban and Small Stream Flood Advisories and/or Flash Flood Warnings
were issued for the following locations:
(in alphabetical order, by state)
- Alabama:
- Sunday: Marshall County.
- More than 3 inches of rain in an hour caused flash flooding in Marshall County.
- Arizona:
- Friday: the Kaibab Plateau and north rim of the Grand Canyon.
- California:
- Friday: the Sierra Nevada Mountains and adjacent foothills from Yosemite south to
Kern.
- All roads in and out of the Yosemite Park were reported closed. Large amounts
of water were still being released Friday from the Mammoth Pool Reservoir.
- The Kings, Kaweah and Kern Rivers were receding and officials were allowing
evacuees to return to their homes.
- The Flood Control District in Merced and Fresno Counties began releasing water
from the Exchequer and Friant Dams respectively. It was recommended that
persons directly below these two reservoirs consider evacuating as water levels
rose.
- Saturday: Fresno, Madera, San Joaquin and Sutter Counties and Small Stream and
River Flood Warnings continue for the northern San Joaquin Valley.
- A Flash Flood Watch with mandatory evacuations was posted for persons in the
area between the
- Sacramento River and the Sutter Bypass south of the Tisdale Bypass and north of
Knights Landing due to a dangerous levee situation on the Tisdale Bypass. This
included the Sutter Basin and the town of Robbins.
- A mandatory evacuation order was issued Saturday night for the Meridian area of
western Sutter County. This was due to a confirmed levee breach on the Sutter
Bypass which occurred in the West McClatchy Road area.
- 4 or more breaks in the San Joaquin River levee about 15 miles west of Fresno
raised the danger that flash flood waters might threaten the town of Mendota
and the Mendota Dam.
- Due to the high flood levels on the main river system in the northern San Joaquin
Valley, many of the smaller rivers and streams are also backing up, continuing
the flooding problems. The high flows are due to high releases from the
reservoirs and continued runoff from the mountains.
- A voluntary evacuation was requested in southern San Joaquin County for the
area near the confluence of the San Joaquin River and the Stanislaus River due to
a possible levee failure.
- Sunday: San Joaquin County.
- A levee break along the south bank of the Paradise cut one quarter mile east of
the Union Pacific railroad tracks caused a flash flood warning to be issued.
- Another levee failed along the San Joaquin River in extreme southern San
Joaquin County. Reports indicated that water from the breach was spilling north
over previously evacuated areas.
- The small river and stream flood warning continued in effect for the central San
Joaquin Valley as high levels if the rivers, specifically the Toulumne and San
Joaquin will continue to cause smaller streams and rivers to backup and flood
low lying areas.
- Montana:
- Friday: Big Horn, Musselshell, Yellowstone, Golden Valley, Carbon, Rosebud,
Treasure, Stillwater, and Custer Counties and a Small Stream Flood Warning for the
Little Salmon River in southwest Idaho County.
- Major flooding on the Little Salmon River has persisted since New Years Day
from the recent rain, snowmelt along with ice jams. The river had returned to
within its banks by Friday afternoon, but the threat of flooding from snowmelt
and ice jams continued.
- Saturday: the Urban and Small Stream Flood Advisory continued for portions of south
central and southeast Montana, including Big Horn, Musselshell, Yellowstone, Golden
Valley, Carbon, Rosebud, Treasure, Stillwater, and Custer Counties.
- Oregon:
- Friday: Deschutes and Wasco Counties.
- Puerto Rico:
- Friday: An Urban and Small Stream Flood Advisory was posted for the north and north
central sections of Puerto Rico from Vega Alta to the west to Camuy.
- Utah:
- Friday: Kane County and extreme southwest Utah.
- Washington:
River Flooding
Rivers and streams with locations either above flood stage or expected to rise above flood stage
include:
(in alphabetical order, by state)
- Arkansas: the White and Cache Rivers.
- California: the Sacramento, Merced, San Joaquin and Tuolumne Rivers.
- Heavy runoff and large dam releases will keep the Sacramento River near the Tehama
Bridge above flood stage through today. Although river stages are receding slowly,
major flooding will also continue through today on the lower San Joaquin and the lower
Tuolumne Rivers. The crest on the San Joaquin River was near Vernalis on Sunday
afternoon.
- Off the mainstem rivers, flood warning continue through today for small rives and
streams in the northern San Joaquin Valley as they attempt to empty into the already
swollen San Joaquin and Tuolumne Rivers.
- Indiana: the Upper Wabash and Kankakee Rivers.
- Iowa: the Iowa River and Beaver Creek.
- The stages on the above are fluctuating above flood stage due to ice action.
- Louisiana: the Atchafalaya River.
- Mississippi: the Tallahatchie River.
- Nevada: the Truckee River from Lake Tahoe to Truckee and from Sparks to Nixon. The
mainstem Carson River between Fort Churchill and Lahontan Dam. The West, East and
Mainstem Walker Rivers.
- Although still high, stages along the entire Truckee River were steady or receding
Sunday afternoon. Stages remained well above flood stage from Lake Tahoe to Truckee
due to high releases from Lake Tahoe. Sparks to Nixon the river was up to 3 feet above
flood stage and steady or receding slowly. Flooding is expected to continue along these
reaches for several days.
- Severe erosion is taking place on the Carson River near Dayton Nevada. This erosion
was due to the Carson River changing its course. Two homes were eroded away by the
river Sunday morning and two more are threatened, as was a sewage line under the
river. The stages on the river are slowly receding and flooding is expected to end above
Fort Churchill today. Releases and/or spill from the Lahontan Dam could cause flooding
on the Carson River below the dam, including the town of Fallon.
- There was record flooding along the Walker River system in the Mason Valley area of
Lyon County Sunday afternoon. Some levees were overtopped, many roads and bridges
were closed or washed out, many homes were flooded and many evacuations had taken
place. There has been widespread flooding throughout the river system. Stages on the
system are steady or slowly falling with exception of major rises expected on the
mainstem Walker River below Weber Dam with probably lowland flooding, but only
minor flooding is expected in the town of Schurz.
- Oregon: the Pudding, Tualatin, Willamette and lower Columbia Rivers. The rivers in Oregon
are all falling and approaching flood stage, if not already below.
- South Carolina: the Lower Santee River.
- Washington: the Cedar and Chehalis Rivers.
- Minor flooding is expected to continue for the above rivers.
Joanna Dionne
Comments are welcome at HIC@noaa.gov
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