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DAMAGE TO BRIDGES HEAVY

By W. A. DOUGLASS, Associate Bridge Engineer

N DECEMBER 1937, a series of structures. Reports indicate that both old structures on sections of
severe storms swept over North- · about forty-five bridges were totally highway recently taken into the sys-
I ern and C e n t r a 1 California, destroyed or seriously damaged. tem. It is interesting to note that
breaking records for concentrated Approach fills were washed out in a both these bridges withstood the flood
rainfall and leaving widespread dam- number of cases. and in three or caused by .the failure of the San
age both to private and public prop- four locations it a.ppears that exten- Francisquito Dam in 1927, when a
erty. Direct and immediate losses to sions to the bridges will be neces- portion of the bridge on the coast
State highway bridges alone exceeded sary. In at least t.en locations en- highway was destroyed. The latter
a half million dollars, and the total tirely new channels were cut across has since been replaced with a modern
cost of repairs and replacement on the highway . and,, . in each case it structure which was not damaged in
State highways is estimated at nearly will be necessary either to provide the March flood while the two older
three million. new bridges or return the streams bridges upstream were seriously dam-
In turn, Southern California was to their former locations. aged.
visited, during the first week: of
_BRIDGES WIPED OUT SANTA CLARA RIVER RAMP AGES
March, 1938, by storms leaving behind
property damage many times that of In western Fresno County, Walt- In the valley of the Santa Clara
the December storm in the north. ham Creek carried a considerable River Highway Route 79 was washed
The areas most seriously affected flow. State Route 10 follows this out in spots and two bridges were
were in Los Angeles, Orange, San stream closely, westerly from Coal- damaged. An old timber structure
Bernardino and portions of Ventura inga, and a number of temporary over the Sespe Creek Overflow at the
and Riverside counties. Effects of crossings as well as a county built westerly edge of Fillmore is practi-
the storm, to a lesser extent, were also concrete bridge were damaged. cally a total loss. Although it is
felt as far north as Monterey and A timber bridge over the Cuyama planned to construct a line change
Fresno counties. Rough preliminary River was washed out near the Santa and eventually abandon this partic-
estimates indicate a direct loss of Barbara-San Luis Obispo county line ular section of road as a State high-
State highway bridges in the March east of Santa Maria. way, a bridge will be necessary to ac-
storm of over one ·and one-half mil- The Santa Clara River flooded tak- commodate through traffic for about
lion dollars. The total loss to State ing out portions of two bridges, one one year and it will continue in use
highways during this storm has been crossing the river near Fillmore and permanently for local traffic.
estimated at over five million dollars. the other near Saticoy. These were Three spans of another old timber

STREAM CONTROL STUDIES
In addition to the restoration of
highways and structures, there will
be the cost of new waterway openings
and extensive protection work:, the
need for which became apparent dur-
ing the recent storm. Extensive
studies of the entire area together
· with the past and probable future
behavior of the streams, planned and
probable stream control work: by other
agencies and property owners and a
number of other factors must be made
before the entire cost may be calcu-
lated. The cost of additional bridges,
bridge extensions, slope protection
and stream control in the immediate
vicinity of highway crossings may
easily cost a million dollars in addi-
tion to the restoration of facilities
destroyed by the flood.
';rhe following data will give an
idea of the extent and character of Bridge under construction across Big Creek on the San S imeon-Carmel coast high -
way in Monterey County. Concrete piers w ithstood flood waters but high w inds blew
the flood damage to State highway down falsework of one arch.

[Ten] (April 1938) California Highways a.nd Public Works

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