The naturally occurring element boron has played a significant role in our watershed. District staff samples water from various locations throughout the watershed , submits them for analysis and then publishes the results each month. The results of the latest analysis are contained in the table below.
| Boron Analysis | Sample Date: 9/17/2024 |
| Sample Location | Results |
| Cache Creek at Moore Dam | 2.2 mg/L |
| Capay Diversion Dam (canal water) | 1.1 mg/L |
| Cache Creek at the Bear Creek Confluence | 1.4 mg/L |
| Bear Creek at the Cache Creek Confluence | 18 mg/L |
| Indian Valley Reservoir Discharge | 0.61 mg/L |
| Indian Valley Reservoir | 0.66 mg/L |
| Cache Creek Dam Discharge | 1.1 mg/L |
| Lakeport | 1.0 mg/L |
The history and concentration levels of boron in Clear Lake, Bear Creek and Cache Creek is discussed in the report “Natural Background Levels of Boron in the Clear Lake-Cache Creek Watershed.”
Local water quality issues, and the factors that influence water quality constituents including boron are discussed in the 2006 report “Boron, Salinity, Nutrients and Dissolved Oxygen in the Irrigation Water within the Yolo County Flood Control & Water Conservation District.”
Nitrate
The average concentration of nitrate in the District’s surface water irrigation supplies is 0.4 mg/l as Nitrate as N. More information regarding nitrate in Cache Creek surface water can be found in the fact sheet: “Nitrate in the Surface Water Supplies of Cache Creek”