Lake Powell May inflows = 400,000 acre-feet #ColoradoRiver

Glen Canyon Dam -- Photo / Brad Udall
Glen Canyon Dam — Photo / Brad Udall

From InkStain (John Fleck):

Lake Powell is ending May with a surface elevation above 3,596 feet above sea level, four feet above the projection when the month began. That’s an extra 400,000 acre feet of water. Lake Mead, less dependent on weather and more dependent on releases from upstream, is nevertheless a foot above its projections, an elevation above 1,076.

The result is a forecast of more than 5 million acre feet of April-July runoff into Lake Powell, up from a forecast of just 3 million acre feet just a month ago. That is still well below the long term mean of just above 7 maf for April through July, but given the slim margins facing water managers right now the bonus water provides a crucial boost.

Before the storms hit, the Bureau of Reclamation forecast showed Lake Powell flirting with a key elevation threshold – elevation 3,575 come Jan. 1. The 2007 reservoir operation guidelines set that as a trigger point that would require water managers to hold more water upstream and reduce deliveries to Lake Mead. That would have meant a lot less water being sent downstream to Lake Mead beginning in October, setting off a cascade of decisions that could have triggered a shortage declaration in the Lower Basin as early as next Jan. 1…

With an extra 4 feet of water in Powell as of today, and more likely because of our “miracle May”, a 2016 shortage is looking far less likely, though we won’t know for sure until the next round of model results come out after the first of the month. My back-of-the-envelope calculations suggest we’re still at risk of a 2017 shortage declaration, but the risk of one in 2016 has dropped dramatically.

More Colorado River Basin coverage here.

#Drought news: Southeastern Colorado reaps the benefits of May rainfall

Click on a thumbnail graphic to view the May 26 and May 5, 2015 statewide maps.

From The Pueblo Chieftain (Jon Pompia):

Southeastern Colorado, parts of which have suffered under heavy drought and very dry conditions since fall 2010, has benefitted immensely from the recent extended period of rainfall.

A Drought Monitor map released by the National Weather Service shows that with the exception of Baca and Prowers counties, and a small portion of Bent, Southeastern Colorado is now drought-free.

Still, Baca and Prowers are not classified as being under drought conditions but rather “abnormally dry.”

According to Paul Wolyn, a meteorologist with the National Weather Service in Pueblo, only one year ago, most of Southeastern Colorado was in an “extreme drought,” with parts of Otero, Crowley and Kiowa counties suffering under “exceptional drought,” the weather service’s most extreme and rare classification.

And just three months ago, most of Southeastern Colorado, as well as Las Animas County, was classified as being in a “severe” drought.

The start of the Southeastern Colorado drought can be traced back to fall 2010. While a NWS map from July 2010 shows the entire western half of the state drought-free, by December of that year, the drought in that same region had become moderate to severe, with Southeastern Colorado seeing the worst of these conditions.

Although there was some relief in 2012, things dried up again in 2013, with most of Southern and Southeastern Colorado designated as being in an extreme to exceptional drought by summer.

In 2014, a string of summer showers improved the picture somewhat before extended rains this spring moved Southeastern Colorado out of the drought classification.