Tag Archives: Silverdale

Dry weather started early this year amid cloudy conditions

UPDATE:
July 5. Greg Johnson, who lives in Hansville and manages the Skunk Bay Weather station there, said the unusually high rainfall in June for Hansville, compared to the rest of the peninsula, was the result of the Puget Sound convergence zone settling over the area on several occasions. Weather conditions brought localized squalls during the month, he said, adding, “This is very unusual for us.”

The reading at Greg’s weather station, 1.98 inches for the month of June, was somewhat lower than the 2.26 inches recorded at Kitsap PUD’s weather station in Hansville.
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Cool, often cloudy conditions have helped obscure the fact that very little rain has fallen on the Kitsap Peninsula over the past two months.

Precipitation in Holly (click to enlarge)

Now that we are in the fourth quarter of the water year, we can see that rainfall levels for this year will be close to average for most areas on the peninsula. What might not be recognized, however, is that April was well above average, while May and June were well below average.

Holly, in the southwest part of the peninsula, received 10.4 inches of rain in April this year — the third wettest April in the record books, which go back to 1991. The wettest April was in 1996, when 13.3 inches fell in the Holly area.

Precipitation in Hansville (click to enlarge)

After April, things went dry. In May, Holly recorded just 0.15 inches, the second driest May on record. The driest May in Holly was 1992, with 0.05 inches. Then June came along this year with 0.95 inches.

Recall that Holly is not far from the wettest part of the peninsula. It has an annual average rainfall close to 80 inches, compared to Hansville at the northern tip, which gets about 30 inches a year. The major difference, according to climatologists, is the “rain shadow” from the Olympic Mountains, which block precipitation that would otherwise fall on Hansville.

Precipitation in Silverdale (click to enlarge)

Oddly enough, something different happened in Hansville in June this year. According to data from the Kitsap Public Utility District, Hansville received 2.26 inches of precipitation in June, compared to Holly with 0.95 inches. Other areas of North Kitsap also received more rainfall than Holly — or Central Kitsap for that matter — but Hansville was the highest. I will need to check with meteorologists to see if they have an explanation.

In April, Hansville was showered with 4.7 inches of rain, and that was the second wettest April on record, behind 2005 with 5.84 inches. In May, Hansville received just 0.39 inches, which was the second driest May behind May of 1992, when 0.35 was recorded.

Large ribbons of Noctiluca, a floating phytoplankton, can be seen in this photo taken June 28 off Poverty Bay near Federal Way in Central Puget Sound.
Photo: Eyes Over Puget Sound, Dept. of Ecology

Silverdale, in the middle of the peninsula, fell into line with 5.1 inches in April, the fifth wettest April on record; followed by 0.13 inches in a dry May, second only to May 1992 with 0.05 inches; and then came June with 0.93, the sixth driest June on record in Silverdale.

The graphs on this page show how the three areas this year (blue line) track with last year (orange), which was a wet year. The other lines represent the average for each area (purple), the maximum annual rainfall (green) and the minimum annual rainfall (brown). To see similar charts for other areas, go to the PUD’s Hydrodata page, click on “Rain Gauge” under the map, and then choose one of the red telemetered locations for the latest information.

Throughout Puget Sound, near-normal temperatures and low rainfall during June resulted in variable freshwater inputs into our inland waterway, according to the latest Eyes Over Puget Sound report (PDF 6.3 mb). A large bloom of the orange plankton Noctiluca has been spreading through South and Central Puget Sound and piling up on some beaches, according to the report. A large growth of green macroalgae also can be seen along some shorelines and drifting on the surface in some waterways, including Port Madison in North Kitsap.

Juvenile salmon have begun migrating out of the estuaries and are confronted with a complex mixture of water temperatures, as revealed by thermal images in the EOPS report.

Below-normal precipitation is expected in the Northwest over the next two weeks and through the end of the water year on Oct. 1, according to both short-term and long-term forecasts by NOAA’s Climate Prediction Center. (Check out the three-month outlook map on this page.) Meanwhile, temperatures in our region are expected to be above average. (See the temperature map.)

We are currently in the midst of a neutral phase in the El Niño Southern Oscillation, an oceanic condition expected to continue through the summer, according to most near-term climate models. Sometime in the fall, ENSO is expected to shift toward an El Niño condition that should continue into the winter, according to a discussion brief (PDF 626 kb) by the Climate Prediction Center.

El Niño conditions normally bring warmer temperatures with less precipitation to our region. A very strong El Niño in 2015 and 2016 led to significant ecological changes. I have not seen a prediction for the strength of the next El Niño, which is predicated upon a heat buildup in the tropical Pacific Ocean, but such ENSO predictions are frequently updated.

Rainfall records are beginning to fall across the Kitsap Peninsula

Water Year 2017, which began on Oct. 1, got off to a rip-roaring start this month in terms of rainfall, and now records are falling for October rainfall totals across the Kitsap Peninsula.

holly

As shown in the three charts on this page, the graph started climbing steeply above the lines shown — including the green lines, which denote the highest annual precipitation recorded for the past 25 to 33 years.

So far this month, 19.5 inches of rain have fallen at Holly, which has averaged about 7 inches in October for the past 24 years. As you can see in the annual rainfall map at the bottom of this page, Holly lies in the rain zone on the Kitsap Peninsula — the area with the greatest amount of rainfall in most years. With four days left in the month, Holly has about an inch to go to break the record of 20.5 inches going back to 1991.

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Extensive floodplain restoration brings new hope to Clear Creek

A giant piece of a cedar log stands erect in a barren landscape north of Silverdale, where a new channel for Clear Creek stands ready to receive water.

An old cedar log was recovered during excavation for a new channel for Clear Creek. Photo: Dunagan
An old cedar log was recovered during excavation for a new channel for Clear Creek.
Photo: Christopher Dunagan

Well, maybe this channel won’t be entirely new. Designers working to restore this portion of Clear Creek studied old maps. They tried to align the new man-made channel to the meandering stream that existed 150 years ago, before farmers diverted the creek around their fields.

During excavation, workers uncovered buried gravel — remnants of the old streambed — along with chunks of cedar that had lain along the edge of the stream. Buried and cut off from oxygen, these pieces of wood survived for decades underground, while cattle grazed in the fields above.

Workers excavating for the new channel used their heavy equipment to pull out what remained of a great cedar log. They stood the log vertical and buried one end in the ground — a monument to the past and future of Clear Creek.

A restored Clear Creek floodplain (before plantings) north of Waaga Way in Central Kitsap. Photo: Kitsap County Public Works
A restored Clear Creek floodplain (before plantings) north of Waaga Way in Central Kitsap.
Photo: Kitsap County Public Works

Chris May, manager of Kitsap County’s stormwater program, showed me the new channel this week. He said it was rewarding to uncover some buried history and realize that the stream would be restored in roughly the same place.

“We found the old channel,” Chris told me, pointing to a deposit of gravel. “We are pretty confident that we got it right.”

This $3-million project has been conceived and designed as much more than a stream-restoration project. The elevations of the land around the stream have been carefully planned so that high flows will spill into side channels and backwater pools. That should reduce flooding in Silverdale and help stabilize the high and low flows seen in Clear Creek.

Before photo: This was the farmers field as it appeared before restoration. Photo: Kitsap County Public Works
Before photo: This was the farm field as it appeared before restoration. // Photo: Kitsap County Public Works

The engineers did not calculate the reduced frequency of flooding, but floodwater storage is calculated to be 18.4 acre-feet, the equivalent of a foot of water spread over 18.4 acres or 29,700 cubic yards or 6 million gallons.

In all, about 30,000 cubic yards of material have been removed across 21 acres, including the former Schold Farm on the west side of Silverdale Way and the Markwick property on the east side. Native wetland vegetation will be planted along the stream and in low areas throughout the property. Upland areas will be planted with natural forest vegetation.

The topsoil, which contained invasive plants such as reed canarygrass, was hauled away and buried beneath other excavated soils to form a big mound between the new floodplain and Highway 3. That area will be planted with a mixture of native trees.

Graphic showing area before restoration. Graphic: Kitsap County Public Works
Graphic showing area before restoration.
Graphic: Kitsap County Public Works

Plans call for removal of 1,500 feet of an existing road with upgrades to two aging culverts. Adding meanders to the straightened channel will create 500 feet of new streambed that should be suitable for salmon spawning.

Plans call for adding 334 pieces large woody debris, such as logs and root wads to the stream. Some of that wood will be formed into structures and engineered logjams to help form pools and gravel bars.

Graphic showing area after restoration. Graphic: Kitsap County Public Works
Graphic showing area after restoration. Notice stream meanders near beaver pond habitat
Graphic: Kitsap County Public Works

“This will be one of the first streams to meet the Fox and Bolton numbers,” Chris told me, referring to studies by Martin Fox and Susan Bolton of the University of Washington. The two researchers studied natural streams and calculated the amount of woody debris of various kinds needed to simulate natural conditions, all based on the size of a stream. (Review North American Journal of Fisheries Management.)

The elevations on the property were also designed so that high areas on opposite sides of the stream would be in close proximity in several locations.

“Beaver will pick that spot,” Chris said, pointing to one location where the stream channel was squeezed by elevated banks on each side. “We want to encourage beaver to come in here.”

Beaver ponds will increase the floodwater storage capacity of the new floodplain and provide important habitat for coho salmon, which spend a year in freshwater and need places to withstand both high and low flows. Because the county owns the flooded property, there won’t be any complaints about damage from beavers, Chris noted.

Aerial photo showing project area with Silverdale in the background, Silverdale Way to the left and Highway 3 to the right. Photo: Kitsap County Public Works
Aerial photo showing project area with Silverdale in the background, Silverdale Way to the left and Highway 3 to the right. // Photo: Kitsap County Public Works

Clear Creek Trail (PDF 390 kb), which begins on the shore of Dyes Inlet, will be routed along the higher elevations as the trail winds through the property. Three new bridges will provide vantage points to watch salmon after vegetation obscures other viewing areas from the trail. Viewing platforms, as seen along other parts of Clear Creek Trail, were not included in this project but could be subject to further discussions.

Count me among the many people — experts, volunteers and users of Clear Creek Trail — who are eager to see how nature responds when water (now diverted) returns to the new stream channel. For decades, the lack of good habitat has constrained the salmon population in Clear Creek. The stream still has problems related to its highly developed watershed. But now a series of restoration projects is providing hope for increased coho and chum salmon and possibly steelhead trout as well as numerous other aquatic species.

In a story in the Kitsap Sun, Reporter Tristan Baurick described work this week on the Markwick property, where fish were removed in preparation for final channel excavation.

Here are some details (including photos) of various Clear Creek projects, as described in the state’s Habitat Work Schedule for restoration projects:

Washington Department of Ecology provided $2 million for the project. Kitsap County’s stormwater and roads programs each provided $500,000.