SWSIReportMay2005

• Title: Colorado Water Supply Conditions Update
• Date: 5/12/2005
• Description: Presentation
• Basin: Statewide
• Drought Mitigation - Doc Type: Presentation

SAN JUAN/DOLORES BASIN

May-05

Basinwide Conditions Assessment
The SWSI value of 1.5 indicates that for April the
basin water supplies were above normal. The Natural
Resources Conservation Service reports that May 1
snowpack is 135% of normal. Flow at the gaging station
Animas River near Durango was 1,620 cfs, as compared to
the long-term average of 771 cfs. Storage in McPhee,
Vallecito, and Lemon reservoirs totaled 102% of normal as
of the end of April.
The SWSI number indicates a lower water supply
than actually exists because major reservoirs were dropped
to make room for upcoming runoff.
With precipitation at 127% of normal in Durango
during April soil moisture continued higher throughout the
basin.
The water supply held up in terms of snow water
accumulation during April in southwestern Colorado. An
extended warm spell melted much of the south facing slopes
at levels up to and above 11,000 feet for a time causing the
snow pack to drop off considerably, but storms at the end of
the month raised snow water ievels back to 135% across the
San Juan-Doiores and San Juan Miguel River Basins. Snow
density was near 45% water on the La Platas at the end of
April. Extraordinary accumulations of snow water were seen
in the La Platas, the Florida River, Los Pinos River and the
San Juan River drainages. More storms early in May were
keeping the content high. especially compared to the
declining average and percentages of normal reached 160%
or higher.
A significant rise in the rivers developed with the
Animas at Durango reaching 2,880 cfs for an average flow.
May 24'h the Dolores at Dolores reached 2,440 cfs and the
San Juan in Pagosa Springs was running at bank full but not
reporting due to removal of the control area as well as
damage to recording equipment. All the reporting streams
ran well above 150% of normal for April.

Outlook
While levels in major reservoirs were lowered in
anticipation of the runoff, most of the other reservoirs in the
area remained full or topped out during the month. Concern
about flooding remains high; however, with most reservoirs
being off.channel and others being reduced, it is expected
that the seasonal cooling and heating will moderate the
runoff. Still, very high flows up to levels seen in past flood
years may occur this year.

Public Use ImDacts
A good water supply was still welcome in the area
and river users as well as recreationists are looking forward
to a good season of water supply.

~"-

~
~

w
~
~
> 0
~
a
z
- .,
>
~
a.,

.

4
Jn96.Ja-'l-97..m93.ffi.6gJEn..OOJa1..01Ja-1.(lZJm.03~J:n.OO

"""'"...

PNM\S R\offi. fIR ~ A..ON"Er( 1/A.1ER YEAR

1.OXl,cm

v ---
/
/
/
1/ V ---
/
~ V
;:.--; /
...-c l:- V ---

t) lDJ,cm
~
~
;.
'I
~ OOJ,cm
o
~
~
w
> 4OO,cm
~
::>
"
a :ro,cm

o
Q:l "" ce::..m Fro"""'''''' M>j..oreJ./y "" """

-El-V\ET(197J)

.....""'(:m2)

___ AVG

-X-aD5

REPRESENTATIVE RESERVOIRS

300.000

250,000

li
~ 200.000
.
f150.{XX)
1;;
~ 100,000

50.000

o

"""""

Valledto

""''''

8A'oV. !l<II3) Contents

1'204I30I05 Contents

9