|Don Pedro Reservoir on January 5 before the storms, elevation about 786 feet (76% of capacity).|
The atmospheric river storms of January have finally subsided, and we are looking at kind of a new landscape across California. We had a couple of sunny days, so we headed up the highway to have a look at Don Pedro Reservoir on the Tuolumne River coming out of Yosemite. When we visited on January 5, the lake stood at 786 feet, which translates to 76% of capacity. That was 114% of normal for this time of year, which was a relief after five years of intense drought.
|Don Pedro Reservoir on January 26 after two atmospheric river storms, elevation 813 feet (90% of capacity).|
When we arrived yesterday, the lake stood at 813 feet, or 90% of capacity, which is 133% of normal. It is only 17 feet below the level of the dam. It could have been higher, but the dam operators have been maintaining constant outflows in the range of 7,000-9,000 cubic feet per second, a level that is just short of flood stage. Had they not done this, the lake could have overflowed and flooded downstream urban areas as happened in 1997.
|Tuolumne River in Waterford, about 8,000 cubic feet per second|
My rain gauge has been active. My friends in more humid regions may snicker a bit when I talk of how we've had 7.38 inches of precipitation in January. That might not seem like all that much but in 25 years of recording rainfall in Waterford, only two had greater amounts, 7.58" in 1995, and 8.60" in 2011. We've had a year where that was the total for the entire season (7.26" in 2014). We've already passed the total rainfall normally received in an average year (14.69" so far compared to 13.92" average for the last 25 years).
But the real story? The snowpack.
At the height of the drought, we had a snowpack that was 5% of normal. 5%! It was both unbelievable and appalling.
And the snow kept falling! The second atmospheric river storm system brought even more snow, and as of today, the snowpack is nearly 200% of normal. If the trend continues (there is NO guarantee of this), we could be on track for a record snowpack. I don't consider it likely, but it would be nice to start recharging the groundwater aquifers that have been severely depleted in recent years.
The record snowpack should not be seen as evidence that global warming isn't happening. Average temperatures are defiinitely up and have been for several decades. The thing is, snow is snow whether the temperature is 15 degrees or 30 degrees. A not-at-all unusual heat wave could undo the progress in the snow levels. The sky spigot could turn off. After the record flooding of 1997, February and March both provided less than a quarter inch of rain over the entire month. And the drought will never be truly over, as demand outstrips supply even in plentiful years. And little is being done to replenish declining groundwater aquifers.
All in all, though, I'm happier to have plentiful rain rather than crippling drought!