Skip to Content

View Benchmark Log

Found it alidade found P 386

Monday, 05 May 2003

USCGS Bm reads - P386 / 1936 - New BM (HT0497) is reset of this one, as barrier rail added decades after bridge built made it impossible to put a survey rod on BM.

This bridge is built atop the Crystal Springs Dam, which when completed in 1890 was (and still is!) the largest concrete-block dam in the world. Originally 120 ft high, in 1911, it was raised to 149 ft. The lake in front of you is but one in a string of four in the San Andreas Valley, containing a collective total of 29 billion gallons. The dam rode out the '06 quake, but if it ever failed, it would flood San Mateo from Coyote Point to Foster City.

Advertising with Us

Return to the Top of the Page