Water History of Santa Barbara County California Drainage Regions California Drainage Regions with Inter-Region Transfer Water History of Santa Barbara County Water History of Santa Barbara County Water History of Santa Barbara County Water History of Santa Barbara County Water History of Santa Barbara County Water History of Santa Barbara County Water History of Santa Barbara County Water History of Santa Barbara County Santa Barbara County Avg Annual Precip Water History of Santa Barbara County 148 Water History of Santa Barbara County 148 Water History of Santa Barbara County Water History of Santa Barbara County Water History of Santa Barbara County Water History of Santa Barbara County Water History of Santa Barbara County Groundwater Basin Profile (Idealized) Before Irrigation from Deep Wells After 40 Years of Irrigating from Deep Wells Cachuma Project History Cachuma Project History 1782 Santa Barbara Presidio 1786 SB Mission 1806 Diversion from Mission Creek for irrigation & grinding grain. Mission dam and reservoir were not sufficient. Additional supplies were needed. 1887 Seven 200ft deep wells 1888 City Engineer made first of many surveys Concluded water was going to waste from the Santa Ynez River Cold Spring Tunnel drilled Not feasible to extend thru mtn Cachuma Project History 1896 - City proposed dam at Juncal site and a tunnel 1902-1913 various proposal for dams on Upper Santa Ynez 1912 Mission Tunnel completed From “Western Construction”, 1918 1918-1920 Gibraltar Dam constructed Lippincott warned of siltation 1928 - Juncal site sold to Montecito 1930 - Gin Chow case confirmed reighs to surplus SYR water 1930 - Juncal Dam completed by Montecito, uses Doulton Tunnel Cachuma Project History 1938 - Bd/Supv authorized water supply studies for South Coast 1939 Report Findings: Groundwater levels “dropping at an alarming rate” Sufficient supply was not available from the coastal area Gibraltar inadequate for future needs Additional supply would have to come from SY River Recommendations: Raise Gibraltar Dam (done in 1949) New dam at Tequepis site on SY River 1940-1941 - Bd/Supv contracted with Bureau of Reclamation and USGS to prepare a County-wide water plan Cachuma Project History 1944 - USBR Report proposed eventual construction of 7 dams: 3 Dams on the Santa Ynez River: Camuesa (upstream of Gibraltar) Tequepis or Cachuma Santa Rosa 1 Dam on Salsipuedes Creek 2 Dams on the Cuyama River: Vaquero (now Twitchell) Cuyama Debris Reservoir 1 Dam on Sisquoc River at the Round Corral site Cachuma Project History Cachuma Project History 1944 – 1945: SBCWA & water districts formed to contract with U.S. 1946 – Dam at Camuesa site rejected 1946 – USBR proposed Cachuma with 275,000 ac-ft storage City and water districts rejected Too large and too expensive 1947 - USBR presented alternatives for Cachuma and Tequepis Dams various capacities with/without provisions for future enlargement 210,000 ac-ft Cachuma selected Water districts and City approved Dec 8 Water Agency approved Severity of drought spurred action Cachuma given priority Cachuma Project History 1948 Cachuma Project authorized. 206 ft high earthfill Dam 210,000 af capacity Tecolote Tunnel South Coast Conduit. 1948 Water rationing in Santa Barbara 1949 Election on Cachuma Project 1949-52 Congress appropriated funds Cachuma Project History Bradbury Dam construction began in 1950 Earth fill structure 206 feet above the stream bed 6,700,000 cu/yds of fill Crest length 2,975 ft Concrete spillway 4 - 50’ x 30’ radial gates Auto open 3 ft for every ft reservoir rises 6,700,000 cu/yds of fill 7 ft horseshoe tunnel contains the outlet works Cachuma Project History Tecolote Tunnel construction began in 1950. Very difficult. 9000 gal/minute Inflows with temperatures up to 117° F. Dangerous accumulations of methane gas and long reaches of rock swelled and squeezed beam supports. Setbacks hospitalized mine workers, delayed the project, increased costs, and forced a change in contractors. Completed in January 1955 Tunnel infiltration Project yield Dried mountain springs & wells Cachuma Project History The South Coast Conduit started in 1950. 26 mile pipeline 10 mile 48 inch Goleta reach first to be finished 16 mile Carpinteria section including 36, 30, and 27 inch pipeline terminates at the Carpinteria Reservoir Regulating Reservoirs Lauro Ortega Carpinteria Glenn Anne Dam & Reservoir The SCC was completed in 1956. Cachuma Project History Cachuma Project History Cachuma Project History 1952 January Floods Would have filled Cachuma Led to SBCFC&WCD 1953 - Dam, Tunnel, and South Coast Conduit completed 1953-58 Period of anxiety waiting Ridicule by project opponents Monument to “New Deal” on dry river If Gibraltar doesn’t fill, how can we expect to fill Cachuma? April 1958 – Cachuma filled and spilled 1971 - Dam renamed for Bradbury Cachuma Project History Design Cachuma Yield : 33,000 ac-ft/yr (1948 calc based on 1908-1947 records) Known: Infl = Inflow into Lake Time Period: One Month Rain = Precipitation on Lake Reservoir Size & Shape Variable: Yld = Annual Yield (by month) Evap = Evaporation Rate Rel = Required Releases Calculate: Evap = Evaporation Loss Stor(begin) = Beginning Storage Spil = Spills Sstor(min) = Target Min Storage Stor(end) = Ending Storage Change in Storage = Inflow - Outflow Stor(end) = Stor(begin) + Infl + Rain – Evap – Rel – Spil - Yld Cachuma Project History Recalculation of Cachuma Yield 1974-1975 by USBR Cachuma Project History Design Cachuma Yield (1948 calc based on 1908-1947 records): 33,000 ac-ft/yr Revised Cachuma Yield (1975 calc based on 1908-1974 records): 34,300,000 m3/yr = 27,800 ac-ft/yr New critical period 1946-1952 Gibraltar Pass Through 1983 City agreed to strengthen Gibraltar Dam for max prob earthquake 1985 City also wanted to raise 20 dam to increase storage to offset loss by siltation Employed consultants 1987 Consultants made presentations to City Council Problems with Least Bell’s Vireo (endangered species) Consultants not consider operational changes A small reservoir upstream of a large reservoir can be very inefficient SBCWA had prepared a Santa Ynez River Operations computer model Ran the SYR model to see if Gib yield could be taken from Cachuma Results showed concept appeared promising Sent a memo to city engineer SYR Hydrology Committee studied concept in depth Committee included representatives from all interested parties Concept deemed feasible City employed consultants to prepare documents 1989 Resulted in the “ 1989 Upper Santa Ynez River Operations Agreement” City preserved yield & saved cost of raising the dam SYR Model Schematic Gibraltar Dredging 1979 Federal “Clean Lakes” grant for dredging Gibraltar $1,150,000 + City matched = $2,300,000 ($7,600,000 in 2017 dollars) Research pgm on dredging contaminated sediments Disposal site north side of lake Used pneumatic pumps (Pneuma system) 40% to 50% solids 713 ac-ft dredged Cost $5,000 to $7,000/ac-ft in 2017 dollars 1983 “City in June 1983 entered into a contract to purchase the equipment for a continuing dredging operation.” Cachuma Operations “Safe Yield” operation vs Overdraft ops Calced amount to safely take in a critical drought Just reach minimum pool at end of critical period But what if in 6th year of a drought of a 7 yr critical period? Continue taking Safe Yield? If not, what do you take? Different strokes for different folks Agencies with various supplies might want full yield Single source Agencies might want conservative draft 1987-1992 drought: Cachuma managers met monthly Agreed to begin shortages when storage = 100,000 ac-ft Agreed shortages seemed prudent at that time Not sufficient for recent drought Cachuma Operations “Safe Yield” operation vs Overdraft ops Calced amount to safely take in a critical drought Just reach minimum pool at end of critical period But what if in 6th year of a drought of a 7 yr critical period? Continue taking Safe Yield? If not, what do you take? Different strokes for different folks Agencies with various supplies might want full yield Single source Agencies might want conservative draft 1987-1992 drought: Cachuma managers met monthly Agreed to begin shortages when storage = 100,000 ac-ft Agreed shortages seemed prudent at that time Not sufficient for recent drought Cachuma Operations 1989 Cachuma operation monthly spreadsheet Reduction Level M&I Draft SY Ag Draft M&I Delivery Factors SY Ag Delivery Factors Assumed Entitlement Delv Schedule Minimum Storage MaxMonthShortage EvapDepth[in] Evap [ft/mon] May 15 Elev 5/15 Credits 5/15 C.O.Storage Requested Delv Rain On Lake Inflow DwnstrmRelease C.O.Storage Use Bishop Ranch Evaporation Lake Diversions DELIVRABL YIELD EndMonthStorage EndMonthArea Cachuma Operations very Factor 0% Projected Cachuma 1990-91 & 91-92 Storage very Factor 0% 20 60,000 ft] - 50,000 40,000 30,000 20,000 10,000 Projected Cachuma Storage [ac 0 0 50 100 150 200 250 300 350 400 Days in Cachuma Water Year from May 15 Cachuma Operations very Factor 50% Projected Cachuma 1990-91 & 91-92 Storage very Factor 50% 20 60,000 ft] - 50,000 40,000 30,000 20,000 10,000 Projected Cachuma Storage [ac 0 0 50 100 150 200 250 300 350 400 Days in Cachuma Water Year from May 15 Cachuma Operations 1996 Cachuma operation studies (not published) Backwards look at 87-92 drought operations Used SYR Model to test droughts as if they occurred at various times in period of record Results not perfect in any regard Cachuma Operations Reservoir Surcharging 1969 Floating Debris Removal Excavating Lake while Low Stilling Basin Cachuma Operations 1969 Santa Ynez River Floods - Warnings not believed or heeded - Needed better origination, dissemination, & reaction Santa Ynez River Flood Warning System - Realtime hydrologic data - Rain - Lake levels - Cachuma gate info - Stream gage data 1976 Santa Ynez River Flood Forecast Model Flood warnings Modified Cachuma Ops for Flood Mitigation Water History of Santa Barbara County “Cap” Twitchell was the Bradbury of the north County.