[circa 2004-03-01]

The California Data Exchange Center (CDEC) installs, maintains, and operates an extensive hydrologic data collection network including precipitation and river stage sensors for flood forecasting. It can be found on the Web at http://cdec.water.ca.gov. CDEC provides a centralized location to store and process real-time hydrologic information on the Sacramento River and other California waterways gathered by various cooperators throughout the State. They disseminate this information to public and private agencies, and the news media. CDEC data is also available to the public.

So what does this mean and how does CDEC apply to recreation on the Sacramento River…

CDEC can be a useful tool for either planning a canoe trip on the river or for just recreating along the bank. Flow information, especially during times of high water and flooding, are extremely helpful in determining conditions on the river.

River flow data is measured in CFS (Cubic Feet per Second). A high CFS reading means more water moving through the channel while a low reading can typically be translated as a slower moving waterway. This is all relative to the size of the river, creek, or stream and historic flow data. Experienced boaters, canoers, kayakers, hunters and fisherman are typically familiar with CFS and know how the reading can affect their favorite waterway.

The CFS reading, whether high or low, has pros and cons from a recreational standpoint. Higher flows mean swifter water and can introduce many hazards to your river experience. If CFS increases suddenly due to rain or other factors, the water level can rise suddenly and carry along substantial amounts of debris.

A low CFS reading, on the other hand, can mean a slower moving waterway with less water in the system and more exposed hazards. An example of this might be a tree or rock that is underwater during “normal” conditions, but becomes a hazard to navigation as water levels drop.

CDEC information is maintained by the Department of Water Resources, Division of Flood Management. Besides river conditions, it also includes other hydrological information including gauges with references, reservoir and water supply data, snow pack status information, and state precipitation totals. It even has a set of data query tools and glossary of terms and acronyms.

Reading this information must not be used to make access decisions but rather as a general guide. The best rule to follow: “Check on hydrologic information ahead of time for reference, but base your recreation decisions on what you actually see out on the river. If it looks too swift or dangerous, then don’t chance it!” If you follow this rule and stick to conditions you are comfortable with, you will enjoy many safe trips along the Sacramento River.

Source: http://cdec.water.ca.gov