The severe drought gripping most of Colorado continues to drop water
levels in local rivers and raise water temperatures, potentially
endangering the health of fish and returning the Roaring Fork to a
trickle in Aspen, as happened in 2002.
The river on Thursday was
running through town at 23 cubic feet per second (cfs), below the
state’s recommended instream flow of 32 cfs, and well off the 115 cfs
average, according to a Roaring Fork Conservancy report.
Besides
the drought, the level is so low because holders of some rights are
allowed to take water and drop the river below the recommended instream
level, which was implemented in the 1970s by the Colorado Water
Conservation Board. The holders can do that because their rights are
senior to the state’s.
“It’s depressing, but senior water rights
often trump instream flow rights,” said Rick Lofaro, the conservancy’s
executive director.
State recommended instream flows, also called
state instream water right levels, are related to preserving the
environment to a reasonable degree, according to the water conservation
board website. There is some debate about what is reasonable, said Tim
O’Keefe, education director for the conservancy.
He said some
local water rights date back to the 1880s and were related to mining;
other rights are for agriculture. The city of Aspen also has a “pretty
old water right,” he said.
The conservancy two weeks ago started a
volunteer program to take temperature measurements of area waterways.
With 40 people taking 150 measurements since the program started, the
conservancy can inform state wildlife officials and fly-fishing shops
about problem areas.
The Roaring Fork near Aspen on Thursday hit
68 degrees, the state standard for a healthy ecosystem, O’Keefe said.
Anything above that affects dissolved oxygen in the stream to the point
that fish get stressed; insects are also affected. If the temperature
rises to 72 degrees, the Colorado Parks and Wildlife Division can shut
down stretches of rivers to fishing.
The Roaring Fork Conservancy
has been discussing the issue with the valley’s fly-fishing shops,
O’Keefe said. Many of the businesses, aware of the temperatures, are
limiting trips for guests to mornings and wrapping up the excursions by
early afternoon.
The Fork below the Fryingpan River is not as
dire, O’Keefe said, because the latter relies on water from Ruedi
Reservoir. The Crystal River at the fish hatchery outside Redstone is
also below the state instream water right level, the group’s report
says.
Recent “rain raised river levels slightly for only a day
or two,” the report says. “River temperatures are getting warmer as
water levels continue to fall.”
O’Keefe said that this year there
are “definitely a lot of comparisons to 2002.” That year’s drought and
low snowpack, combined with diversions for senior water rights,
transformed the Roaring Fork into a watery skeleton of its usual self
for two weeks in August.
“If we get rain it could be comparable” to 2002, he said. “If we don’t get rain, it could be worse.”
For ways to lessen the effects of the drought, go to www.roaringfork.org/sitepages/pid404.php [1].
