Yakima WATERS Field Trip
July 11-12, 2011
Yakima River Basin Field Trip
July 11-July 12, 2011
Day 1 – Overview and upper Yakima raft trip
8:30 – Coffee and introductions
9:00 Overview
Carey Gazis – Geology*
Steve Wagner or Jamie Lamperth – The river continuum*
Carey Gazis – Field trip overview
Stop 1 – new Ellensburg municipal well
Carey Gazis – Ellensburg city water supply
Stop 2 – Roadcut on State Route 10*
Meilani – clast identification mini-lesson
Stop 3 – Rte 10 overlook
Lisa Ely – River terraces*
Begin float trip at Teanaway River crossing of Rte 10
Stop 4 to 6 – points along float
Dale -- Macroinvertebrate surveys
Sarah Healas – Fish mini-lesson
Kelsey Johnson – tree mini-lesson
Stop 7 – West Ellensburg Park
Dinner (5:30 p.m.), recap and questions
* Additional information in packet
Day 2 – Yakima River Canyon and lower Yakima River basin
8:30 – meet at CWU
Stop 8 – Taneum Creek
Tiffany Bishop – Effects of the 100-year flood on Taneum Creek
Renee Holt –nitrate measurement mini-lesson
Stop 9 – Cherry Creek return flow
nitrate measurement
Stop 10 – Beavertail bend
Lisa Ely – debris flows*
Stop 11 – Umtanum Creek, lunch
Steve Wagner – Amphibians
Jon Hegna – beaver mini-lesson
Eric Inions – vegetation mini-lesson
Stop 12 – Mt. Baldy
Carey Gazis – Yakima fold-and-thrust belt
Stop 13 – Roza Dam
Discussion of dams, salmon hatcheries programs
Stop 14 and 15 – Selah stops
Jessica – airphoto mini-lesson
Lisa Ely – Selah stream restoration site, nitrate measurement
* Additional information in packet
Figure 1. The Yakima River Basin, Washington.
From Jones, Vaccaro, and Watkins (2006). Hydrogeologic Framework of Sedimentary Deposits in Six Structural Basins, Yakima River Basin, Washington U.S.G.S. Scientific Investigations Report 2006–5116
Figure 2. Land use and land cover, Yakima River Basin, Washington, 1999 (From Fuhrer and others, 2004.)
Fuhrer, G.J., Morace, J.L., Johnson, H.M., Rinella, J.F., Ebbert, J.C., Embrey, S.S., Waite, I.R., Carpenter, K.D., Wise, D.R., and Hughes, C.A., 2004, Water quality in the Yakima River Basin, Washington, 1999-2000: U.S. Geological Survey Circular 1237, 44 p.
Figure 3. Selected tributaries, diversion canals, return flows, and streamflow-gaging stations, Yakima River Basin, Washington. (From Fuhrer and others, 2004.)
Yakima watershed geology in a nutshell
Long, long ago on a continent, not so far away…
· Before 200 million years ago
This area DID NOT EXIST as rocks at all – it was just ocean with sediments quietly collecting on the basin floor. The coast of North America was over in Montana somewhere.
· ~200 millions years ago
SUBDUCTION starts off the coast of North America. The coast was still somewhere in Idaho or eastern Washington.
· Since 200 million years ago
Through subduction, land has been gradually added by plastering on ocean sediments, building volcanoes, intruding of granite, and ACCRETED TERRANES (rocks, often islands, that are carried in by the subducting plate and scrapped off onto the continent).
· 65-35 million years ago
SEDIMENTS eroded off the mountains and got deposited into a valley. Swamps flourished leaving black goop that eventually became coal (think Roslyn mines!). Basalt lava came up in places and flowed across the surface. Much of it eventually got folded as the subduction and compression continued.
· 15-14 million years ago
COLUMBIA FLOOD BASALTS. Massive outpouring of basalt from the Oregon-Idaho boarder spread across much of what is now Washington and northern Oregon. 175,000 cubic km (for comparison, Mt St Helens was ~1 cubic km).
· 15 million years ago - now
Tectonic forces between the North American plate and the ocean plates has led to north-south compression in this area and a series of folds have developed (Manastash Ridge, Umtamum Ridge, Selah Ridge, Saddle Mountain, etc). Between the folds, the valleys have filled with river gravels, mud, volcanic deposits (Kittitas Valley, Selah Valley, Yakima Valley)
· Last 2 million to ~15,000 years ago
ICE AGE – Glaciers draped copiously over the Cascades and carved our valleys in the upper Yakima watershed (like Lake Cle Elum).
SUMMARY CROSS-SECTION
Adapted from Field Trip Guidebook to the Natural History of Kittitas County – J. Mabry
The River Continuum Concept (RCC)
The River Continuum Concept is the idea that the biological components and processes of rivers show changes along a longitudinal downstream continuum. In general, the headwaters (low order streams) are small and steep with swift, cool water that is shaded by riparian vegetation. These streams have mostly allochthonous energy inputs from leaves, needles and stems that fall into the stream each autumn. The invertebrate community is composed mostly of shredders and collectors as very little periphyton is available for grazers. The fishes have body shapes that enable them to move easily in swift water and mouths that are adapted to feeding on shredders and collectors. The P/R ratios here are usually less than 1.0.
The mid-reaches of rivers have more of the channel exposed to sunlight and substrates that allow for the growth of periphyton. The invertebrate community is composed of mostly grazers and collectors as there is less CPOM available for shredders and more of the energy is in the form of autochthonous inputs. Larger fishes are present as more food is available and larger pools provide habitat and cover. The P/R ratios are usually greater than 1.0 due to the high level of photosynthesis from periphyton.
In the lower reaches, the river has a low gradient and substrates are usually composed of gravel, sand and silt that do not allow for periphyton growth. The energy inputs generally come from upstream sources of FPOM that support a mostly collector invertebrate community. The fish are generally more slow-water adapted species that feed on zooplankton in the water column or bottom-oriented fishes that feed on detritus.
Citation:
Vannote, R. R., G. W. Minshall, K. W. Cummins, J. R. Sedell, and C. E. Cushing. 1980.
The river continuum concept. Canadian Journal of Fisheries and Aquatic Sciences 37: 130-137.
Glossary:
Allochthonous inputs - Energy inputs to a stream food chain that come from outside the stream
Autochthonous inputs- Energy inputs to a stream food chain that come from within the stream via photosynthesis
Collectors – Aquatic insects that consume FPOM by filtering water
CPOM – Coarse particulate organic material
DOM – Dissolved organic material
FPOM – Fine particulate organic material
Grazers (or Scrapers) – Aquatic insects that have mouthparts used to scrape periphyton from stream substrates
Lentic – A term referring to standing waters (such as lakes)
Lotic – A term referring to flowing water (such as rivers)
Periphyton – Photosynthetic organisms (usually algae and bacteria) that grow on steam substrates
P/R Ratio – The ratio of primary production (photosynthesis) to respiration
Shredders – Aquatic insects that use chewing mouthparts to consume CPOM
Stop 2 (Ellensburg Formation) and Stop 3 (Thorp terraces),
The following is an excerpt from Mabry, J.J., 2000. Field Trip Guidebook to the Natural History of Kittitas County, in Mabry, J.J. The Concept of Place-Centered Education as a Model for Enviromental Literacy and Natural Resource Management, M.S. Thesis, Central Washington University, p. 35.36, 45-49. Available from CWU Dept. of Geological Sciences or CWU library.
The Thorp -Teanaway Glacial Features Guided Tour
The North Cascades of Washington extend from Snoqualmie Pass to the Canadian Border and contain 750 glaciers. The North Cascade Range separates the state into two separate climatic regions. The glaciers associated with the features in Kittitas County flowed down three main drainages (rivers) of the eastern slopes of the North Cascade Range. These drainage areas occupied the areas of Keechelus, Kachess, and Cle Elum Lakes.
Five stages of alpine glaciation are identified as originating on the high peaks of the Cascade Crest. The physical evidences of these five glacial stages remains today and are represented by landscape features of terminal moraines,
graded outwash terraces, and correlating stratigraphic sequences.
Figure 16. Glaciers and their extension into Kittitas County, Modified from Porter, 1969
The illustration above (Figure 16) depicts the positions of glaciers that created the features seen on the landscape today. Glaciers created and occupied the basins of lakes Keechelus, Kachess, and Cle Elum and flowed down the river valleys of the Yakima and Cle Elum Rivers.
The glaciation of this region that occurred during the geologic time period called the Pleistocene, from about 2 million years ago to 500 years ago. When the climate of the region became colder the ice accumulated on the peaks of the Cascades and flowed down the eastern slopes toward the Kittitas Valley. When the climate warmed the glaciers receded back toward the Cascade crest, but left outwash deposits and evidence of their existence and positions throughout the region.
The sharp features seen on the high cascade peeks are cirques, horns, arêtes, and hanging valleys. The evidence found along the glaciers’ lower routes are U-shaped valleys, basin lakes, and striations in the bedrock. The sediments associated with the glaciers are called moraines, eratics, till, outwash, and loess.
Scientists use techniques like pollen analysis, carbon dating, radiometric dating, and weathering and erosional features to determine the age and relationships between different glacial events in the region. A technique developed by University of Washington professor Stephen Porter was to measure weathering rinds.
Weathering rinds are concentric bands of oxidized minerals found in the basalt rocks moved by the glaciers. The wider the band of oxidation, the older the sample rock is. When compared to other basalt samples, found on different glacial moraines, a relative age date can be given to determine when the glacier placed the rock.
This tour of the glacial features circles the area around Lookout Mountain. The tour begins outside Ellensburg on the canyon road to Cle Elum, State Route 10. The tour begins at the Wenatchee turn-off sign at U. S. Route 97 then proceeds toward Cle Elum to the northwest on State route 10 to the junction at State Route 970. At the 970 and 10 junction the tour turns (right) back to the northeast until meeting up at the north junction of U. S. Route 97 at Virden, which takes you back to south toward Ellensburg.
SET ODOMETER AT 0.0 AT THE JUNTION OF STATE ROUTE 10 and U.S. ROUTE N97 (THE TURN-OFF TO WENATCHEE)
Mile As you enter this section of the tour there are numerous
0.0 features to be seen but very few safe parking areas. Where pull-off points are available a number of features will be pointed out. The first features are the “Thorp Gravels” seen on the right hand side (north) of S.R. 10. These are the same gravels found in Craig's Hill in Ellensburg and discussed in the Craig’s Hill tour. Good exposures of these gravel deposits are visible from about mile point 0.6, after you pass under the railroad trestle, to mile 3.7 to the first parking area located on the left side of the road.
This gravel formation is constantly changing and has been for hundreds
of years. If you look along the face of the ridge there is evidence of older slides, along a similar surface area. The older slumps are now re-vegetated and the ages of the trees help to determine when the slump occurred. The whole area was cut into by the Yakima River and exposed both the “Thorp Gravels” and a portion of the Ellensburg Formation.
Mile The largest slump occurred in June of 1970 when a portion of the
3.2 road was closed due to the massive amount of gravel covering the area. The mass of gravel blocked the Yakima River for a time and fishermen in the river witnessed the river “drying up” down stream of the blockage. This portion of the road was re-built on-top-of the landslide, as the costs to remove the gravel exceeded the costs to build a new road.
Mile The first stop is located ahead on the left side of the road. Here the
3.7 ”Thorp Gravels,” Figure 17, are exposed best. They are believed to be between 3 and 4 million years old and were name after of the community of Thorp. The whole structure is made up of individually layered beds made of gravel and sand. It is not well consolidated, continually weathers, and is prone to continuing erosion and landslides.
Figure 17. “Thorp Gravels” along the north side of State Route 10
This whole area has experienced the giant landslides called ‘slumps.’ Slumps are the result of the gravels being saturated by water, primarily from irrigation run-off. The water enters the gravel formation and percolates through it causing the whole formation to erode very quickly. The water can often be seen on the cliff face where it seeps out and discolors the surface.
Figure 18. Ellensburg Formation along the north side of State Route 10
Mile The exposure of the Ellensburg Formation at this location, above,
5.7 is one of the most interesting to geologists. The exposure here is the middle portion of the Ellensburg Formation, overlain by the “Thorp Gravels.” This exposure is made up of sandstones, sitlstones, conglomerates, and thick layers of volcanic ash called lahars.
The lower portion is made up of sandstones, mud, volcanic mud flows (lahars) and small packets of gravel. The features on the surface are made by the weathering of the surface by wind and water. This area too is continually eroding away, and rocks continuously fall from above. A hard hat is a good idea if you plan to approach the area for a closer look.
From this area on, the most predominant features on the landscape are the terraces located primarily on the south side of the river. The diagram below Figure 19, from Porter 1976, shows the relationships of the different terraces in the upper Yakima River Canyon to the location of the river today. Shown in this diagram are the loess and soils developed on top of the glacial outwash.
Figure 19. Glacial Terraces along the Yakima River, Modified from Porter, 1976
Mile The tour continues by driving onto the top of the Thorp Drift.
6.5 From this stopping point, and for the next half-mile, the road grade steepens. The elevation change is due to the incline onto the terminal moraine that marks the furthest advance of the Thorp Glacial stage.
The area ahead is rich with wildlife. Bald Eagles and Osprey make this area their home. Watch for Eagle nests and pairs of birds fishing for dinner in the Yakima River. This area is also a crossing point for deer and elk and they can often be seen at dawn and dusk heading to the river for a drink.
_________________________________________________________________
Stop 3:
Yakima River WATERS Project
Water Quality Handout