Over 50 Wet Systems

A Delta Debate: Rating "X"

This is an "X" issue that is only provocative to those deep inside California water policy who are wonky enough to know what "X" means.

In the water-speak of the Sacramento-San Joaquin Delta, "X" is a measurement of distance. It represents the number of kilometers (the federal government in this case regulates via the metric system) upstream from the Golden Gate Bridge where the Delta begins to turn a tad salty. This water has a defined salinity of 2 parts of salt per thousand. (Ocean water is 35 parts per thousand. Fresh water is less than half a part per thousand.)

In the Delta, the location of this mixing zone constantly changes based on the pulses of the tides and the fresh water flows arriving from the upstream tributaries. Wherever this imaginary line is, it is known as X-2.

Delta water project operations have some ability to manipulate the location of X-2. Releasing less water from upstream reservoirs can cause X-2 to move upstream because there is less fresh water pushing the saltier water downstream. Conversely, releasing more water from reservoirs can move X-2 downstream. So can pumping less water from Delta water projects to the Bay Area, Central Valley and Southern California. So can some combination of the two actions.

Such manipulations under the Endangered Species Act (ESA) have never been required in the fall - until perhaps this year. ESA regulations enacted three years ago ( as part of a so-called "biological opinion" ) require a specific location for X-2 in the fall months after a very wet winter such as the one we just experienced. And that location is 74 kilometers (46 miles) upstream of the Golden Gate. The rationale, a subject of much debate, is to expand the low-saline habitat to help the struggling delta smelt population. If this year's winter hadn't been quite so wet, the same regulations would have called for X-2 to be located 81 kilometers (50 miles) upstream of the Golden Gate. If precipitation had been perfectly average, ESA regulations don't require X-2 in the fall to be precisely anywhere (although state water quality standards for the Delta still apply and affect X-2).

It would take a significant release of additional water and reduction in pumping this fall, something estimated at roughly a quarter trillion gallons, in order to push X-2 westward to the 74-kilometer imaginary line to comply with these regulations. The future impact on water supplies could be significant, depending on whether next year is wet (the reservoirs refill) or dry (they don't). Hence a debate. A federal district judge in Fresno held four days of hearings recently to better understand the science and potential water supply impacts of regulating X-2. Stay tuned.

Workweek Starts Out Wet; Sunshine, Cooler Temps by Week's End

A series of weather systems will travel across the region bringing periods of showers and thunderstorms to start the week. Sunshine returns for Wednesday along with cooler temperatures. A slow-moving low pressure system over eastern Iowa will travel across northern Ohio tonight and into Tuesday keeping the threat of showers and thunderstorms across Tuscarawas County tonight and Tuesday.

Regional radar indicates that scattered showers and thunderstorms continue to move across the eastern half of the area with additional development to the west and southwest. The activity should exit the region this evening with increasing thunderstorm coverage from west to east overnight tonight.

This second phase of stormy weather and precipitation is associated with a surface low set to move across the region later tonight. Showers and thunderstorms will be likely across the entire Tuscarawas Valley overnight and into Tuesday morning.

Severe weather is not expected. However, areas in southwestern Ohio have been highlighted by the Storm Prediction Center for severe thunderstorms early Tuesday. The widespread cloud cover should serve to limit any severe weather developing over our area but some of the stronger thunderstorms over the southwest may survive long enough to filter into east central Ohio.

The low will continue moving east through Tuesday and should be well east of the Tuscarawas Valley by Tuesday evening.

The chances of showers and thunderstorms will remain in the forecast for Wednesday due to a cold front pushing across the Great Lakes. Once the front crosses the region Wednesday afternoon, high pressure will build in from the west.

Temperatures across the Valley will be much cooler by Wednesday night will temperatures dropping into the mid 50s. Highs Thursday will only reach the upper 70s. The high will provide abundant sunshine and clear skies Thursday and Friday.

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Although every effort has been made to provide timely and accurate weather information on this web site, the information presented here is for personal use only and should not be used to make critical life or death decisions, or descisions relating to the protection of property.

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