WATFMeetingSummaryApril2008

• Title: April 2008 Drought Update
• Date: 4/15/2008
• Description: Joint Water Availability and Colorado Flood Task Force Meeting Summary
• Basin: Statewide
• Drought Mitigation - Doc Type: WATF Meeting Summary

1..1
D!'I'AltTl\,II'NT or
NATURAL
RESOURCES

COLORADO DIVISION OF
UWATER RESOURCES

DEPARTMENT OF NATURAL RESOURCES

APRIL 2008 DROUGHT UPDATE

Water Availabilitv Task Force Co-Chairs

Veva McCaig, CWCB - 303-866-3339
Email [e-mail]

Jack Byers, DWR - 303-866-3581
Email [e-mail]

Executive Summary
Colorado continues to experience cooler than average temperatures, The eastern plains of Colorado is the only region to
have average temperatures, Forecasters predict La Nina* will continue for the next few months extending into the
summer. The snow pack statewide remains above average which means the runoff is going to be above average or normal
in every basin, High snow pack has helped keep temperatures cool in the mountains which have delayed the snowmelt,
The eastern plains did not experience sufficient moisture in March and thus is experiencing a low level drought. Western
Colorado is drought free, benefiting from winter snowfalL Strong La Nina's, like the current one, tends to last more than
one year and droughts are tied to multi year La Nina's,

**

.

Statewide, Colorado's snowpack is 128% of average, Most basins are still above average snowpack The
Arkansas basin is 149% of average which is their highest snow pack in the state, The South Platte basin is the
lowest but is still above average at 107%,

.

With median snowfall, the snowpack statewide is projected to be 130% of average by May 1st, The snowpack
for the nOlihern half of the state is projected to range from 108-139%, The snowpack for the southern half of the
state is projected to be well above average ranging from 136-157% of average, With median snowfall until June
1 st, statewide snowpack is projected to be 155% of average, Projections for the Arkansas basin are 232% and the
lowest average projection belongs to the South Platte basin at 98%,

.

Statewide, reservoir storage ranges from 92%-107% of average, Many basins will increase levels in their
respective reservoirs from the snow melt run off This is the case in the Colorado River basin which has 61 'Yo
capacity and the Arkansas basin at 33% capacity, All of the major reservoirs on the South Platte had finished
filling towards the end of March, but conditions may change if irrigation users diveli water due to lack of
rainfall ,

.

According to the Colorado Water Supply Index (SWSI)**, the values range from a high value of +3,6 in the
Gunnison basin to a low value of +0.2 in the Yampa/White basin, The South Platte basin's SWSI value
improved to + 1. L which is near normaL The Gunnison basins had the highest SWSI value at +3,6,

.

Colorado's streamflow forecast statewide remains in the 90-150% of average range, Most basins are expected to
have above average runoff The Gunnison, Rio Grande and Arkansas basins are projected to have high stream
flows,

.

Local officials in the Rio Grande basin are now less fearful of damaging floods during the 2008 runoff season,
Runoff levels in the basin might just be slightly above normaL

Sea slllface temperatures at the Equator in the Pac!flc Ocean impact global climate patterns, Depending on
these patterns, Colorado could be experiencing El Nif'io or La Nif'ia conditions,

SWSI values are based on snowpack, reservoir storage and precipitation for the winter period (Nov-ApJ),