Deadpool Diaries: Lower Basin use on track to be lowest in nearly four decades

Projected Lower Colorado River Basin water use, as a percentage of each state’s total allocation

 

I’ve emerged from my cozy book writing cave (The new book’s going well, thanks for asking!) to some stunningly optimistic Lower Colorado River Basin water use data.

Forecast use in 2023 (based on the Sept. 18 USBR forecast model) has dropped below 6 million acre feet, currently just 79 percent of the total baseline Lower Basin allocation of 7.5 million acre feet. Californians are on track for their lowest take on the river since 1949, according to my crazy stitched-together dataset (USBR decree accounting reports plus pre-1964 numbers assembled some time ago by some folks at MWD).

Arizona and Nevada’s use is the lowest its been since 1992.

Relative to their baseline allocations, Arizona (at 69 percent) and Nevada (at 65 percent) are still doing the heaviest lifting, but California (at 86 percent) is seriously pitching in too.

State/Total 2023 Use (acre-feet) % of Total Allocation Last Year Use Was This Low
Arizona 1,921,944 68.64% 1992
California 3,788,609 86.10% 1949
Nevada 193,599 64.53% 1992
Total US Lower Basin 5,904,152 78.72% 1984

 

Because bits are cheap, here’s the full dataset back to 1964. Source is the USBR’s Water Accounting reports, with a huge thanks to Sami Guetz at UCSD for help earlier this year QA’ing the numbers:

year Arizona California Nevada total
1964 1,127,176 5,064,733 25,297 6,217,206
1965 1,008,531 4,899,987 22,716 5,931,234
1966 1,073,055 5,096,912 26,656 6,196,623
1967 1,106,894 4,886,734 27,190 6,020,818
1968 1,169,240 5,072,533 33,614 6,275,387
1969 1,138,085 4,896,527 37,392 6,072,004
1970 1,201,441 5,015,018 38,308 6,254,767
1971 1,296,930 5,216,300 50,586 6,563,816
1972 1,203,043 5,230,635 81,051 6,514,729
1973 1,268,744 5,317,547 92,649 6,678,940
1974 1,325,631 5,414,040 94,889 6,834,560
1975 1,358,003 4,983,705 72,140 6,413,848
1976 1,248,020 4,706,594 73,192 6,027,806
1977 1,231,274 5,097,343 73,174 6,401,791
1978 1,234,942 4,503,340 71,293 5,809,575
1979 1,150,853 4,788,423 60,074 5,999,350
1980 1,169,657 4,725,496 92,426 5,987,579
1981 1,415,850 4,795,949 110,017 6,321,816
1982 1,240,384 4,299,799 102,326 5,642,509
1983 1,062,169 4,245,045 86,596 5,393,810
1984 1,122,399 4,677,103 101,492 5,900,994
1985 1,194,208 4,778,749 101,709 6,074,666
1986 1,356,930 4,803,676 112,217 6,272,823
1987 1,734,172 4,891,961 108,863 6,734,996
1988 1,922,737 5,039,679 129,420 7,091,836
1989 2,229,967 5,144,417 156,213 7,530,597
1990 2,260,272 5,219,457 178,111 7,657,840
1991 1,864,360 5,005,595 180,224 7,050,179
1992 1,906,071 4,546,192 177,551 6,629,814
1993 2,246,695 4,835,017 204,402 7,286,114
1994 2,152,410 5,234,088 227,542 7,614,040
1995 2,221,346 4,925,480 217,439 7,364,265
1996 2,714,754 5,322,652 249,248 8,286,654
1997 2,853,886 5,250,119 242,777 8,346,782
1998 2,566,707 5,045,228 245,303 7,857,238
1999 2,727,960 5,194,380 291,130 8,213,470
2000 2,802,758 5,162,211 321,984 8,286,953
2001 2,841,028 5,254,718 315,429 8,411,175
2002 2,969,230 5,365,609 326,718 8,661,557
2003 2,830,599 4,408,746 298,392 7,537,737
2004 2,784,645 4,316,185 283,006 7,383,836
2005 2,428,469 4,344,258 291,778 7,064,505
2006 2,782,866 4,335,299 292,864 7,411,029
2007 2,783,323 4,370,695 300,312 7,454,330
2008 2,752,497 4,498,810 269,654 7,520,961
2009 2,831,711 4,358,074 248,613 7,438,398
2010 2,780,367 4,356,839 241,437 7,378,643
2011 2,781,108 4,312,661 222,847 7,316,616
2012 2,789,667 4,416,718 237,161 7,443,546
2013 2,778,867 4,475,789 223,563 7,478,219
2014 2,774,661 4,649,734 224,616 7,649,011
2015 2,604,732 4,620,756 222,729 7,448,217
2016 2,612,833 4,381,101 238,326 7,232,260
2017 2,509,503 4,026,515 243,425 6,779,443
2018 2,632,260 4,265,525 244,103 7,141,888
2019 2,491,707 3,840,686 233,996 6,566,389
2020 2,470,776 4,059,911 255,568 6,786,255
2021 2,425,736 4,404,727 242,168 7,072,631
2022 2,014,176 4,445,255 223,670 6,683,101
2023 1,921,944 3,788,609 193,599 5,904,152

3 Comments

  1. The difference between median values and ’23 (to date) is not much. Mean, too, pretty close. EXCEPT California! -26% IF I got that about right? What happened there? More GW pumping? Wet winter? If it’s just weather, not much to get excited about?

    Thanks, Craig

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