DROUGHT & RAINFALL INFORMATION

Current Conditions

Lake Casitas Water Level Ventura River Water District Groundwater Level Current Rainfall Automated Daily Rainfall Report Current Streamflow Ojai Valley Basin Well Water Levels (Static/Nonpumping) Historic Rainfall & Streamflow Data   Drought In January, 2014, the Governor declared a Drought State of Emergency for California, and in April called on citizens to redouble their efforts to conserve water. The Governor has urged an immediate 20% reduction in water use.   Lake Casitas Water Level and Drought Water users in the Ventura River watershed have been asked by local water districts to voluntarily reduce their water use. The water level of Lake Casitasis at its lowest point since 2004, and can be expected to decline to 50 percent capacity by September, 2014. The 50 percent of full capacity is a critical point at which Casitas Municipal Water District will consider implementing additional water conservation requirements and actions to reduce the rate of water use. When the district makes this decision, other local suppliers that rely upon Lake Casitas water are expected to follow suite.   Wet and Dry Cycles in the Ventura River Watershed The watershed has long experienced cycles of wetter years and drier years. The storage capacity of Lake Casitas was designed by the Bureau of Reclamation based upon the longest dry period on record, the years 1944/45 to ’65. figure1   Wet (blue) and Dry (orange) Periods in the Ventura River Watershed Source: Ventura River Watershed Management Plan (draft 2014) Rainfall Rainfall is highly variable in the watershed—seasonally, and from year to year. Rainfall typically occurs in just a few significant storms each year, which can come any time between October 15 and April 1, with 90% of the rainfall occurring between November and April. Snowfall is generally minimal and short-lived. The Ventura River watershed’s rainfall patterns vary geographically. The rainfall totals from the watershed’s three climate zones shown in the table below illustrate that, on average, the watershed’s upper areas receive over twice as much rainfall, almost 20 inches more, as its lower areas. Precipitation Map
Table 2.2.1.3 – Rainfall Average and Median (inches/year)
Station # Water Years Average Median Min Max
Matilija Canyon 207 1960-2012 35.17 28.74 28.74 89.05
Downtown Ojai 30 1906-2012 21.31 19.20 6.88 49.20
Downtown Ventura 66 1873-2012 15.46 14.12 4.62 38.65
     figure2 Ojai’s Historical Rainfall Since 1906, annual rainfall in downtown Ojai has ranged from a low of 6.88 inches in 1924 to a high of 49.20 inches in 1998—a sevenfold variation. Average rainfall over this period was 21.33 inches. Since 1906, 67% of the years have had less than average rainfall in downtown Ojai. In this period, there have been 15 years of significantly high rainfall in downtown Ojai. (Significantly high rainfall years being those defined as having rainfall at least 150% above the average—or greater than 32 inches.)   As variable as its rainfall may be, the Ventura River watershed does have the distinction of receiving more rainfall than other watersheds in Ventura County. In 2005, 97 inches of rainfall was recorded on the Murrieta divide above Matilija Creek. The peak historic rainfall intensity was approximately 4.04 inches per hour measured during a 15-minute period at the Wheeler Gorge gauge in the mountains adjacent to Ojai.