Santa Barbara County Public Works Department

Overview

The Hydrology Section collects, analyzes, and maintains hydrologic data for many locations throughout Santa Barbara County including Buellton, Cuyama, Lompoc, Los Alamos, Santa Barbara, Santa Maria, and Santa Ynez. Available hydrologic data kept by the Santa Barbara County Flood Control District (SBCFCD) includes rainfall records provided by a network of rainfall observers as well as a network of gages operated by the District. Rainfall analysis is performed by the SBCFCD's Hydrology Section to determine long and short rainfall depth duration and return period information. This information is primarily intended for use by inter- and outer-agencies to determine minimum design requirements for culverts, flood channels, water detention structures, bridges, etc.

View Daily Rainfall Map and Data

View Depth Duration Map and Data

View Monthly Rainfall Map and Data

Typical Rainfall Gages

Wedge and Tipping Bucket Recording gages

Standard, Weight Measurement Punch Tape, and Weight Measurement Chart Recording gages

Gage Descriptions

Rainfall gaging equipment includes wedge gages, standard gages, and data logging tipping bucket gages. The purpose and function of each gage varies and a brief description of each follows:

Wedge Gage

A clear plastic receptacle approximately 14 inches long in the shape of a wedge with a rectangular opening that allows rainfall to enter. Rainfall level is measured by reading the graduated scale on the outside of the gage. This gage has a limited 6-inch capacity and must be emptied often during large rainfall events.

Standard Gage

A metal canister approximately 24 inches in height with an 8-inch diameter collection ring and funnel. The funnel leads to a 2-inch capacity inner collection tube that allows rainfall readings to 0.01 of an inch. Once the 2-inch capacity is exceeded the tube overflows into the 8-inch canister. A rainfall measurement is taken by using a specialized reading stick that is designed specifically for the inner collection tube. The overall capacity of this gage is 20 inches. This gage is most preferred by the hydrologic community and is appropriately named "Standard Rainfall Gage."

Data Logging Tipping Bucket Gage

This type of gage allows rainfall to be measured accurately while automatically dumping the rainfall catch upon each tip. The housing is approximately 24 inches in height with an 8 inch funnel that directs the rain catch into the tipping bucket. Each tip represents 1/100th of an inch of rainfall, thus 100 tips equals one inch. A read switch is activated upon each tip and an electronic pulse is sent to a logging unit encased in a watertight housing. The computer board on the logging unit dates and time-stamps each incremental tip. A laptop computer is then used to download this data from the memory module on the logging unit at each station. The capacity of these units is approximately 80 inches of rainfall and only have to be visited once or twice per year for downloading data and calibration of the tipping bucket mechanism.

The data provided from tipping bucket gages is already in digital format and is easily uploaded to other computers. The digital data is then analyzed and manipulated by software programs that produce long and short depth duration and return period information that can be used in establishing minimum design criteria for a variety of projects.

Latest Rainfall Amounts and Reservoirs Level Report (click on below table to view in Adobe PDF format)

Last updated: July 27, 2006