Solano Project

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SOLANO PROJECT

History

The idea for the development of the Solano Project was conceived in the 1940's and 1950's to meet the water demands of agriculture, municipalities and military facilities within Solano County. As agriculture developed in the County, use of groundwater increased substantially. Groundwater overdraft persisted in several parts of the County. This overdraft condition provided the impetus for a surface water supply to offset the overdraft. The population of Solano County in the 40's and 50's was also expected to grow; however, planners at that time had no way of knowing that the urban population growth in Solano County would increase as dramatically as it has over the past three decades.

During the planning of the Solano Project, Napa County and Yolo County were asked if they wished to participate in a larger Solano Project. Napa and Yolo declined, so the Solano Project was sized to meet only the projected water needs of Solano County. Congressional authorization was granted for the construction of the Solano Project and the first water was delivered in 1959. The total construction cost for the Solano Project was $38 million. For a more detailed history of the Solano Project, see the book by the Solano Irrigation District entitled "The Solano Water Story: A History of the Solano Irrigation District and the Solano Project."

Riparian Water

Riparian stream flows are defined as nay surface water derived from precipitation or rising groundwater that, given prevailing hydrologic conditions, would occur in Lower Putah Creek in the absence of the Solano Project. Non-riparian water, such as treated wastewater and agricultural return flows originating from a non-riparian source (e.g., pumped groundwater that would not otherwise be tributary to the creek) cannot, by definition, be diverted by riparian water right claimants and, therefore, is not included as a source of riparian water from Lower Putah Creek.

SCWA's riparian water availability forecasts for Lower Putah Creek are based on stream flow conditions observed in the Putah Creek drainage, upstream of the Putah Diversion Dam, in the prior (i.e., antecedent conditions) and current water year. Forecasts are made on January 1, March 1 and May 1. The January 1 and March 1 forecasts, which are made before the current rainy season is over, are based in part on projected stream flow conditions for the balance of the rainy season, while the May 1 forecast, the final forecast for the water year, is based on actual runoff measured to date. Both the January 1 and March 1 forecasts include three scenarios, based on the assumption that the balance of the rainy season will either be "wet" (25% exceedance), "normal" (50% exceedance) or "dry" (75% exceedance).

In order to address the differing sources and durations of riparian stream flows (surface stream flows from Putah Creek and/or tributaries to Putah Creek, or rising groundwater), Lower Putah Creek has been divided into five reaches. Water availability forecasts are made for each reach.

Here is the most current RIPARIAN FORECAST.