Severe drought is settling in across most of Western Washington
— including Kitsap County — where dry conditions raise the risks of
wildfire, and low streamflows could impair salmon spawning this
fall.
Western Washington is one of
the few places in the country with “severe” drought.
Map: U.S. Drought Monitor, Richard Tinker, U.S.
agencies.
Scattered showers and drizzle the past few days have done little
to reverse a drying trend as we go into what is normally the driest
period of the year, from now through August. As of today, the fire
danger is moderate, but warmer weather could increase the risk
substantially within a day or two.
The topsy-turvy weather that I observed across the Kitsap
Peninsula last quarter (Water
Ways, April 2) continued through June. Normally, the southwest
corner of the peninsula near Holly receives twice the precipitation
as the north end near Hansville. But that didn’t happen last month,
when the monthly rainfall total was 0.61 inches in Holly and 0.83
inches in Hansville. Silverdale, about halfway between, received
1.11 inches in June.
If you are hosting out-of-town visitors this Thanksgiving
weekend, it might be a good time to take them salmon-watching — or
go by yourself if you get the urge to see one of nature’s marvelous
phenomena.
Rainfall in Hansville. Blue
line shows current trend.
Graph: Kitsap Public Utility District
Kitsap County’s Salmon Park on Chico Way near Golf Club Road
tops my list of places to watch salmon. Expect to see plenty of
dead fish as well as live ones, as we have apparently passed the
peak of the run.
Dogfish Creek near Poulsbo also has a fair number of chum at
this time, with a good viewing spot at the north end of Fish Park.
Gorst Creek and other streams in Sinclair Inlet are known for their
late runs of chum salmon, which are likely to be spotted right up
until Christmas at Otto Jarstad Park.
UPDATE: April 24, 2015
Cliff Mass, professor of atmospheric sciences at the University of
Washington, says in his
blog that it is too early to be predicting severe drought in
Western Washington this summer because of possible late-spring
rains:
“I believe the media and some local politicians have gotten a
bit too worried about our ‘drought.’ We have NOT had a
precipitation drought at all….we are in a snow drought due to warm
temperatures. The situation is unique and I suspect we will weather
this summer far better than expected.”
—–
The word seems to be getting around about the record-low
snowpack in the mountains, which could create a shortage of
drinking water and even lead to problems for salmon swimming
upstream. Read about Gov. Jay Inslee’s expanded drought emergency, issued
today, as well as the last
update from the U.S. Department of Agriculture.
Kitsap Peninsula and the islands of Puget Sound are in their own
worlds, fairly insulated from what is happening in the higher
elevations. In these lower elevations, the key to water supplies is
rainfall, not snow, and the outlook for the year is normal so
far.
As you can see from the charts on this page (click to enlarge),
this year’s rainfall has been tracking closely the long-term
average. If the rains are light and steady, much of the water will
soak into the ground and recharge the aquifers where most area
residents get their water. The aquifer levels tend to rise and fall
over multiple years, depending on the rainfall.
Casad Dam on the Union River, which supplies a majority of
Bremerton’s water, filled in January, well ahead of schedule, said
Kathleen Cahall, water resources manager for the city. The dam is
scheduled for a normal drawdown, and Kathleen said she does not
expect any water shortage.
“We filled the reservoir fairly early this year,” she said. “We
are looking pretty good for the summer.”
October, the first month of the water year, was unusually wet,
Kathleen said. December precipitation also was high. The other
months were fairly normal for precipitation.
Precipitation in the Puget Sound region is expected to be below
average for June, July and August, according to models by the
NOAA’s Climate Prediction
Center. Interestingly, large portions of the Central and
Southwest U.S., Alaska and Florida can expect above-average
precipitation. See U.S. map.
Streams on the Kitsap Peninsula are fed by surface water flows
and shallow aquifers. At the moment, most of the streamflows are
near their historical average. That’s not the case for the larger
rivers in the Northwest, which rush out of the mountains. Most are
well below their normal flows, as shown by the map with the
dots.
Low streamflows usually mean higher temperatures and stress for
salmon. Low flows also can affect fish passage in some stretches of
the rivers while also reducing spawning areas.
While things look fairly good on the Kitsap Peninsula now,
things can change quickly. We have different vulnerabilities than
elsewhere. Climate-change models predict that rains will grow more
intense in the future without changing annual precipitation very
much. That means more of the water will run off the land and less
will soak in, potentially reducing aquifer levels over time.
Managing those underground water supplies will become more and more
critical.
Climate change appears to be altering the flow characteristics
of Puget Sound salmon streams, and the outcome could be an
increased risk of extinction for chinook salmon, according to a new
study.
I’ve long been interested in how new housing and commercial
development brings more impervious surfaces, such as roads,
driveways and roofs. The effect is to decrease the amount of water
that infiltrates into the ground and to increase surface flows into
streams.
Chinook salmon
Photo: Bureau of Land Management
Stormwater experts talk about how streams become “flashy,” as
flows rise quickly when it rains then drop back to low levels,
because less groundwater is available to filter into the
streams.
The new study, reported in the journal “Global
Change Biology,” suggests that something similar may be
happening with climate change but for somewhat different
reasons.
Climate models predict that rains in the Puget Sound region will
become more intense, thus causing streams to rise rapidly even in
areas where stormwater is not an issue. That seems to be among the
recent findings by researchers with NOAA’s Northwest Fisheries
Science Center and Washington Department of Fish and Wildlife:
“Over the last half century, river flows included in our
analysis have become more variable — particularly in winter — and
these changes are a stronger predictor of chinook population growth
than changes in average winter flows or climate signals in the
marine environment.
“While other impacts to this ecosystem, such as habitat
degradation, may be hypothesized as responsible for these trends in
flow variation, we found support for increasing flow variation in
high-altitude rivers with relatively low human impacts.”
Joseph Anderson of WDFW, an author of the report, told me that
chinook salmon, listed as threatened under the Endangered Species
Act, may be particularly vulnerable to dramatic changes in
streamflows. That’s because spawning chinook tend to show up before
winter storms arrive — when the rivers at their lowest levels. The
fish are forced to lay their eggs in a portion of the river that
will undergo the most forceful flows once the rains begin to
fall.
High flows can scour eggs out of the gravel and create serious
problems for emerging fry, Joe said. Other factors may come into
play, but the researchers found a strong correlation between the
sudden variation in streamflows and salmon survival.
In the lower elevations, where development is focused, flow
variability could result from both impervious surfaces on the land
and more intense rainstorms. Efforts to infiltrate stormwater into
the ground will become even more important as changes in climate
bring more intense storms.
Stormwater management is an issue I’ve written about for years,
including parts of last year’s series called “Taking the Pulse of
Puget Sound.” See
Kitsap Sun, July 16, 2014. Rain gardens, pervious pavement and
infiltration ponds are all part of a growing strategy to increase
groundwater while reducing the “flashiness” of streams.
Other strategies involve restoring rivers to a more natural
condition by rebuilding side channels and flood plains to divert
excess water when streams are running high.
According to the report’s findings, the variability of winter
flows has increased for 16 of the 20 rivers studied, using data
from the U.S. Geological Survey. The only rivers showing less
variability were the Cedar, Duwamish, Upper Skagit and
Nisqually.
The effect of this streamflow variability was shown to be a more
critical factor for chinook survival and growth than peak, total or
average streamflow. Also less of a factor were ocean conditions,
such as the Pacific Decadal Oscillation and related ocean
temperature.
Eric Ward, of Northwest Fisheries Science Center and lead author
on the study, said many researchers have focused attention on how
higher water temperatures will affect salmon as climate change
progresses. High-temperature and drought conditions in California,
for example, could damage the organs of salmon, such as their
hearts.
Salmon swimming up the Columbia River and its tributaries could
encounter dangerously warm waters as they move east into areas
growing more arid. Some salmon species are more vulnerable to
temperature, while streamflow may be more important for others.
Coho salmon, for example, spend their first summer in freshwater,
which makes extreme low levels a critical factor.
Eric told me that further studies are looking into how various
conditions can affect each stage of a salmon’s life, conditions
that vary by species. One goal is to build complex life-cycle
models for threatened species, such as chinook and steelhead, to
determine their needs under the more extreme conditions we can
expect in the future.
When it comes to water rights in Washington state, it seems to
me that the Legislature is trying to sell survival suits on a
sinking ship.
Because of budget problems, the Legislature last year slashed 25
percent of the Department of Ecology’s staff in the program that
studies water resources and issues water rights. As you can see
from Ecology’s map at right (click to enlarge), more than 7,000
water rights are pending, and the backlog is growing.
The latest move is to expedite applications where groups of
people are willing to pay for studies to determine if water is
available. Reporter Chris Henry wrote about the approved
Senate Bill 6267 in yesterday’s
Kitsap Sun.
The new law allows a group of water-rights applicants to get
together and pay for the studies needed to process water rights for
a given area. Anyone not willing to contribute to the study must
wait in line for Ecology to get around to processing their water
rights. So the new law works well for water utilities, which have
enough money to pay for the studies. It may or may not work well
for farmers and others who have limited dollars, depending on their
share of the costs. Continue reading →
