An unnamed tributary of Calabazas Creek starts at an elevation of on Table Mountain, whose summit is at and located at 37°15'30" N and 122°04' 55" W, although the creek's official
USGS source is at and located at 37°16'29" N and 122°04'07" W. Named tributaries of Calabazas Creek include Prospect, Rodeo and Regnart Creeks. Prospect Creek flows 1.4 miles before entering Calabazas Creek from the left (heading downstream) at elevation 325 feet, then Rodeo Creek from the right, and finally, Regnart Creek joins at elevation 226 feet. Historically Calabazas Creek was a tributary of
Saratoga Creek joining it just downstream of San Francisco Road (probably
El Camino Real) on the Thompson and West 1876 map, and thence to the
Guadalupe River. When the Guadalupe River was redirected from Guadalupe Slough to Alviso Slough (formerly Steamboat Slough), Calabazas Creek was extended directly to meet Saratoga Creek at the beginning of Guadalupe Slough at Sunnyvale Baylands Park in
Sunnyvale. Thirty-two percent of its length, approximately 4.2 miles, is classified as "hard bottom" and the reach between Highway 101 and Lawrence Expressway is a trapezoidal, concrete-lined channel. From Guadalupe Slough to Highway 101, Calabazas Creek is an enlarged earthen channel with levees. The culvert at Saratoga-Sunnyvale Road was widened and the upstream detention basin completed in September, 2011. ==Habitat and wildlife==