Wenatchee River –Nason Confluence Project Concept Design Report SUBMITTED TO
Yakama Nation Fisheries
Wenatchee River –Nason Confluence Project Concept Design Report
SUBMITTED TO
Yakama Nation Fisheries PO Box 151 Toppenish, WA 98948 PREPARED BY
Inter‐Fluve, Inc. 501 Portway Ave., Suite 101 Hood River, OR 97031
June 30, 2015
Nason Confluence Project – Concept Design Report
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Table of Contents
INTRODUCTION ................................................................................................................................... 1
Overview .......................................................................................................................................... 1
Project Area Description ................................................................................................................... 1
Goals and objectives ........................................................................................................................ 2 Regional Habitat Objectives and Priorities ........................................................................................... 2 Upper Wenatchee River Reach Assessment and Habitat Restoration Strategy ................................... 3
SITE CONDITIONS AND ANALYSIS ......................................................................................................... 4
Fish Use and Habitat Conditions ....................................................................................................... 4
Geomorphology ............................................................................................................................... 5
Hydrology ........................................................................................................................................ 6 Seasonal Hydrology ............................................................................................................................... 6 Peak Flow Hydrology............................................................................................................................. 7
Site Survey and Data Collection ........................................................................................................ 8
Hydraulic Modeling .......................................................................................................................... 8
PRELIMINARY DESIGN CRITERIA ........................................................................................................... 9 Habitat .................................................................................................................................................. 9 Geomorphology/Hydrology .................................................................................................................. 9 Engineering and Risk ............................................................................................................................. 9 River Safety ........................................................................................................................................... 9 Construction Impacts .......................................................................................................................... 10
DESCRIPTION OF PROJECT COMPONENTS .......................................................................................... 10
Component 1: Wenatchee Mainstem Large Wood and Off‐Channel Enhancement .......................... 10
Component 2: Nason Left Bank Large Wood and Off‐Channel Enhancement Site A ......................... 11
Component 3: Nason Left Bank Off‐Channel Enhancement Site B ................................................... 12
Component 4: Nason Right Bank Large Wood and Side‐Channel Enhancement ............................... 13
REFERENCES ....................................................................................................................................... 14
Appendix A – Hydraulic Modeling Output
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Introduction OVERVIEW
This report presents concept designs for aquatic habitat restoration at the Nason Confluence project area
in Chelan County, WA. This project area contains approximately 900 feet of Nason Creek upstream from
the confluence with the Wenatchee River, and 700 feet of the Wenatchee River. The purpose of this
project is to enhance habitat for Endangered Species Act (ESA) listed Chinook, steelhead, and bull trout.
Lower Nason Creek and the mainstem Upper Wenatchee River were identified in the 2014 Upper
Columbia Salmon Recovery Board (UCSRB) Regional Technical Team (RTT) Biological Strategy (UCRTT
2014) as Tier 1 watersheds of highest protection priority. Nason Creek was listed as the highest priority
watershed for restoration in the entire basin, with the mainstem Upper Wenatchee River ranked as
second highest out of eleven assessment units evaluated. Restoration in the Nason Confluence project
area is important because it contains major spawning areas for spring Chinook and steelhead, while also
supporting coho and bull trout for a portion of their life cycle. Stream functioning in the project area is
currently impaired due to reduced large wood recruitment, channel complexity, and gravel recruitment.
PROJECT AREA DESCRIPTION
The project area includes the lower 900 feet of Nason Creek and 1,200 feet of streambank along the right
bank of the mainstem Wenatchee River. The area is approximately 13 acres in size (Figure 1). The
confluence occurs at river mile 53.7 along the Wenatchee River, only 0.5 miles downstream from the
outlet of Lake Wenatchee. Except for portions of the active point and mid‐channel bars, the project area,
including the islands in the mainstem Wenatchee, are vegetated with a mix of trees and shrubs. A large
island near the confluence in the Wenatchee River has a large log jam at its apex that creates pool habitat
off its south and west ends. An alcove 600 feet upstream from the confluence on the Wenatchee River
offers backwater habitat. All property within the project area is United States Forest Service.
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Figure 1. Overview of project area and landownership. The project is located within US Forest Service land.
GOALS AND OBJECTIVES
Regional Habitat Objectives and Priorities
Regional objectives for salmonid habitat protection and restoration in the Upper Columbia Region have
been evaluated and summarized in the document A Biological Strategy to Protect and Restore Salmonid
Habitat in the Upper Columbia Region (2014) by the Upper Columbia Salmon Recovery Board (UCSRB)
Regional Technical Team (RTT). This Biological Strategy is part of the Upper Columbia Spring Chinook
Salmon and Steelhead Recovery Plan (UCSRB 2007) and recommends region‐wide biological
considerations and approaches for salmonid habitat restoration and protection actions. The RTT guides
the development and evaluation of salmonid recovery projects within the Upper Columbia Region.
The Biological Strategy has identified several assessment units within the major watersheds of the Upper
Wenatchee River. The Nason Confluence project area falls within the Upper Wenatchee Assessment Unit.
Both the Upper Wenatchee mainstem and Nason Creek are Tier 1 watersheds of highest protection
priority. Nason Creek is the highest priority watershed for restoration in the entire Wenatchee River
Basin, while the Upper Wenatchee River is the second highest. The Upper Wenatchee River is considered
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a major spawning area for spring Chinook and steelhead, a stronghold for summer Chinook, and a bull
trout overwintering area. Nason Creek is a major spawning area for spring Chinook and steelhead, a
stronghold for coho, and a bull trout overwintering area (UCRTT 2014).
All Chinook spawning that occurs in Nason Creek occurs in the lower 15 miles of the mainstem, which
also contains the poorest quality habitat (UCRTT 2014). The 2014 Biological Strategy identified the
following factors impairing habitat conditions in the Upper Wenatchee River and Nason Creek:
Reduced large wood recruitment, channel migration, and gravel recruitment due to the state
highway, railroad, and private land development.
State highway cut off a large oxbow near the Nason Creek confluence.
Reduced large wood recruitment and channel complexity due to historic logging.
The RTT has prioritized a list of restoration actions to address these factors impeding salmon recovery
goals for the Upper Wenatchee Assessment Unit. Actions that are relevant to the Nason Confluence
project area are listed below (UCRTT 2014):
1. Channel structure and form: Restore habitat diversity by enhancing large woody material
recruitment, retention, and complexity.
2. Peripheral and transitional habitat: Improve fish access to oxbows and historical side channels
that have been cut off from main channel.
3. Riparian condition: Improve riparian conditions to improve long term LWD recruitment.
Wenatchee River Subbasin Plan Key Management Strategies
The Northwest Power and Conservation Council (NWPCC) completed the Wenatchee Subbasin Plan in
2004 to identify and prioritize actions needed to recover listed salmonids in tributary habitats within the
Columbia River Basin (NWPCC 2004). This document identified the following limiting factors for
salmonids in Nason Creek: key habitat, floodplain connectivity, habitat diversity, channel stability,
sediment, flow, temperature, obstructions, and competition.
Key management strategies for Nason Creek that are relevant to the Nason Confluence project area
include (NWPCC 2004):
Improve elevated stream temperatures in the lower mainstem (below Mill Creek) by improving
low flow conditions, channel confinement, and degraded riparian conditions
Reduce fine sediment level in the lower mainstem
Improve riparian and floodplain characteristics in the lower mainstem (below Mill Creek) where
feasible
Improve in‐channel attributes in the lower mainstem.
Upper Wenatchee River Reach Assessment and Habitat Restoration Strategy
The Upper Wenatchee River stream corridor assessment, which covered the mainstem of the Wenatchee
River from RM 35.5 at the upstream end of Tumwater Canyon to RM 54.5 at Lake Wenatchee, was
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completed in 2012 by the Yakama Nation (Inter‐Fluve 2012). The goal of the assessment was to evaluate
aquatic habitat and watershed processes in the Upper Wenatchee River and to identify specific habitat
restoration strategies. This effort included assessments and development of restoration strategies within
the Nason Confluence project area.
Restoration strategies were developed by comparing existing aquatic habitat conditions to target
conditions obtained from reference areas and regional habitat thresholds. Reasons for impairment in the
Nason Confluence project area included impaired off‐channel habitat, lack of cover in existing backwater
areas, and impaired channel migration associated with the state highway bridge over the Wenatchee
River. The following restoration actions were recommended:
Enhance connectivity to off channel habitat
Address artificial confinement within the Nason Creek fan area
Incorporate bar apex jams to control grade and raise the channel bed over time
Place large wood along the channel to increase pool habitat and channel complexity
Site Conditions and Analysis FISH USE AND HABITAT CONDITIONS
Current fish use in the project area includes ESA‐listed spring Chinook (endangered), steelhead
(threatened), bull trout (threatened), and non‐listed summer Chinook, coho, and westslope cutthroat
trout. Spring and summer Chinook, coho, steelhead, and bull trout all utilize the Wenatchee River and/or
Nason Creek in the project area for migrating, spawning, and rearing. Past redd counts show the
presence of Chinook and steelhead spawning in the confluence area, as well as near the riffle in Nason
Creek at the upstream end of the project area (Figure 2) (UCSRB 2004). Adult migration through the
project area has been impaired by lack of large wood and low number of pools, which provide velocity
refuge for migrating adults. The project area also contains poor rearing habitat due to lack of large wood,
low habitat diversity, and lack of off‐channel habitat. According to the Subbasin Plan (NWPCC 2004),
lower Nason Creek has the poorest quality fish habitat of any tributary in the upper Wenatchee Subbasin.
Restoring habitat in lower Nason Creek could increase populations of Chinook, coho, steelhead, and bull
trout.
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Figure 2. Steelhead redds were observed within the project area at the mouth of Nason Creek, while Chinook redds were observed both at the mouth and in the channel of Nason Creek.
GEOMORPHOLOGY
The project area includes approximately 900 feet of lower Nason Creek and its floodplain as well as
approximately 1,200 feet of streambank along river‐right of the mainstem Wenatchee River. Within the
project area, the average gradient of Nason Creek is 0.38% and the average gradient of the Wenatchee
River is 0.33%. Immediately upstream from the confluence the channel of Nason Creek has been
characterized as a glide. The glide has low habitat complexity (no log jams and only a few pieces of large
wood). Upstream from this glide, at the upper‐most portion of the project area, is a riffle. At the
downstream end of the riffle on river‐left is a large gravel bar. A large active point bar is located on river‐
right at the confluence itself. The substrate is composed of gravels and small cobbles. The substrate on the
bed of the channel is loose and unarmored, suggesting regular active sediment mobilization and
deposition.
Within the project area, Nason Creek and its active floodplain surfaces are partially confined.
Confinement on the western border (river‐left side) is by a steep hillslope composed of glacial till deposits
and on the eastern border (river‐right side) by a low alluvial terrace composed of Nason Creek fan
deposits and the armored road embankment of Highway 207 (at the upstream end of the project area).
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Vegetation on the active low floodplain surfaces are dominated by thick stands of alder and vine maple.
Large conifers, with less‐dense undergrowth, cover the higher active floodplain surfaces. The floodplain
along river‐left of Nason Creek has a well‐vegetated riparian zone with two backwater features that are
partially connected to Nason Creek and the Wenatchee River. The largest backwater feature runs along
the toe of the glacial till deposits that constrain the western border of the project area. The downstream
end of this backwater is wetted during low flow. The floodplain along river‐right of lower Nason Creek
contains a high‐flow channel that runs along the toe of the alluvial terrace behind the point bar feature at
the confluence. This feature is activated during high‐flow events from Nason Creek and then empties into
the Wenatchee River.
Channel migration in Nason Creek is limited within the project area, as well as up and downstream.
Upstream from the project area, riprap and other bank armoring confine natural migration along river‐
right at privately owned properties. The armored road embankment of State Highway 207 that runs
along the eastern border (river‐right side), and upstream of the project area, disconnects Nason Creek
from a large oxbow complex as well as Nason Creek’s historical alluvial fan. The Highway 207 bridge
abutments and related riprap also constrain the location of the Wenatchee River and thus the dynamic
processes that historically occurred at the confluence between the two rivers.
HYDROLOGY
Seasonal Hydrology
The Upper Wenatchee River is a snowmelt‐dominated system (Figure 3). The snowmelt runoff typically
occurs during spring and early summer, and is driven by changes in ambient air temperature, snowpack
mass, and the elevation distribution of the season’s snowpack. Peak runoff usually occurs from April
through July, with the highest rates occurring in late June. The Wenatchee returns to baseflow in
September.
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Figure 3. Mean monthly flows for the Wenatchee River below the Nason Creek confluence. Monthly average flows were calculated using data from the USGS gage ‘Wenatchee River at Plain, WA’ and correcting for the project site using a basin‐area correction.
The hydrology of the study area is significantly affected by Lake Wenatchee. Temporary storage in the
lake buffers the snowmelt runoff signal from the Little Wenatchee and White River, which contribute 40%
of the total annual runoff to the Wenatchee. Thus, runoff from some of the highest elevation, and highest
precipitation, regions of the basin are moderated by temporary storage in Lake Wenatchee.
Peak Flow Hydrology
Flood frequency data for the project area were obtained from the basin hydrology work performed by the
US Bureau of Reclamation as part of the Nason Creek Tributary Assessment (USBR 2008). As part of the
USBR analysis, peak flow estimates were generated using the USGS regional regression equations and a
regional gage analysis. The results for three locations within the confluence area are provided in Table 1.
Table 1. Peak flow estimates for three locations within the confluence area at a range of flood recurrence intervals. Data obtained from US Bureau of Reclamation hydrologic analysis (2008).
Recurrence Interval (years)
Discharge (cfs)
Wenatchee above Nason Confluence
Nason at mouth Wenatchee Below Nason Confluence
2 6,817 908 7,725 5 9,082 1,391 10,473 10 10,784 1,775 12,559 25 13,180 2,340 15,520 50 15,156 2,822 17,978 100 17,304 3,361 20,665
0
500
1000
1500
2000
2500
3000
3500
4000
4500
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Discharge
(cfs)
Month
Mean Monthly Flow at Nason Confluence Project Area(Wenatchee River below Nason Confluence)
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SITE SURVEY AND DATA COLLECTION
Topographic and bathymetric data were collected April 6‐10 and May 27‐29 of 2015 using rtkGPS and
total station survey equipment. The bathymetric data were collected using a single beam echosounder
mounted to a inflatable cataraft and tied into survey control on site. The data collection focused on
capturing channel cross sections for hydraulic modeling, as well as topographic points in floodplain areas
to inform design. We relied on existing LiDAR data for other floodplain areas where restoration actions
are unlikely to occur. Control points were placed on the state highway bridge as well as the gravel bar
located at the confluence.
To locate the survey data in space, we collected static data at the rtkGPS base station, and the data were
adjusted using the National Geodetic Survey’s (NGS) Online Positioning User Service (OPUS). The
surveyed data were based on the Washington State Plane North coordinate system with the North
American Datum of 1983. Metadata from the NGS solution indicated a root mean squared error within
0.007 meters for the horizontal coordinates and 0.004 meters for the elevation.
HYDRAULIC MODELING
Existing channel and floodplain hydraulics were simulated using the U.S. Army Corps of Engineers
Hydraulic Engineering Center River Analysis System (HEC‐RAS 4.1.0; USACE 2010). HEC‐RAS is a
computer program that models the hydraulics of water flow through natural rivers and other channels.
The program is one‐dimensional, meaning that there is no direct modeling of the hydraulic effect of
lateral cross section shape changes, bends, and other two‐ and three‐dimensional aspects of flow. The
hydraulic model calculates channel and floodplain water surface elevations, velocities, depths, and shear
stresses (among other metrics) for various input flows.
The model geometry was developed using topographic and bathymetry data obtained through surveys
completed in April and May 2015 by Inter‐Fluve. Survey data were supplemented with LiDAR
(Watershed Sciences 2007) data in select locations. Model geometry for existing conditions were sampled
from the combined Inter‐Fluve ground base survey and LiDAR. Cross sections extended through the
floodplains to the valley walls. The 2‐, 5‐, 10‐, 25‐, 50‐, and 100‐year recurrence interval floods were
modeled as well as a number of low flows. The lowest flow included in the model of 468 cfs was the
lowest average daily discharge recorded on a calendar day at the Wenatchee River USGS gage at Plain,
with the same calendar flow from the USGS Chiwawa gage subtracted. Values for Manning’s n
coefficient of hydraulic roughness were estimated from professional judgment to be 0.038 along the
cobble‐bedded channel and 0.060 along the moderately vegetated floodplains. The models were run in
subcritical mode with a downstream normal depth boundary condition based on an energy slope slightly
higher than the model reach results to avoid an artificial backwater condition.
Proposed conditions were not modeled at this conceptual level and will be included as part of later
phases of design. Many of the project elements include backwater and side channel enhancements or
creations along the floodplain and would not impact the mainstem hydraulics. Large wood along the
mainstem banks would increase Manning’s n values slightly but are not anticipated to have a significant
impact on channel hydraulics. The results of the modeling are presented in Appendix A.
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Preliminary Design Criteria A suite of preliminary design criteria have been developed that incorporate stakeholder objectives, the
RTT Biological Strategy, the Yakama Nation Reach Assessment, physical river constraints, construction
impacts, aesthetics, and recreational user risk. Design criteria serve three primary purposes: 1) to clearly
document and communicate specific project objectives and constraints, 2) to help inform and guide the
design process so that objectives are met, and 3) provide a basis for future performance monitoring. The
design criteria include preliminary performance criteria as well as prescriptive criteria. The design criteria
will be refined as the design process moves forward and as more information becomes available to make
criteria more specific and quantitative. The design criteria are divided into 6 categories: Habitat,
Geomorphology/Hydrology, Engineering and Risk, River Safety, and Construction Impacts.
Habitat
Improve habitat conditions for ESA‐listed salmon and steelhead, using the RTT prioritized
actions for the Upper Wenatchee Assessment Unit (UCRTT 2014), including the following:
o Channel structure and form: Restore habitat diversity by enhancing large woody
material recruitment, retention, and complexity.
o Peripheral and transitional habitat: Improve fish access to oxbows and historical side
channels that have been cut off from main channel.
o Riparian condition: Improve riparian conditions to improve long term LWD
recruitment.
Geomorphology/Hydrology
Design projects that are consistent with current and projected hydrologic and geomorphic
patterns and processes
Allow for naturally dynamic and deformable processes to operate, within the constraints
imposed by existing landownership, infrastructure, and safety considerations
To the extent possible, design side‐channels to maintain sediment transport continuity in order to
maximize design life and reduce in‐filling
Engineering and Risk
Do not increase flooding or erosion risk of public or private infrastructure
Provide adequate ballasting of placed logs to withstand high flows that overtop the structures
(i.e. compensate for buoyancy)
Specific stability and other design criteria of placed structures to be determined in subsequent
design phases
River Safety
Take into account visibility of structures from upstream
Take into account structure form to minimize entrapment potential
Minimize channel encroachment to the extent possible to allow for avoidance by river users
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Construction Impacts
Minimize impacts to intact wetland habitat
Minimize impacts to fish during the construction process by reducing the need for dewatering
and worksite isolation during construction
Locate and configure construction access routes to utilize existing access where possible and to
minimize impacts to existing mature riparian vegetation
Utilize onsite resources or plan channel alignments to take advantage of existing natural features
where feasible (e.g. trees, beaver dam locations)
Description of Project Components COMPONENT 1: WENATCHEE MAINSTEM LARGE WOOD AND OFF‐CHANNEL ENHANCEMENT
Description and Potential Benefits
This component includes two primary elements: 1) large wood habitat cover along the banks of the
mainstem Wenatchee and within an existing small alcove, and 2) the creation of a new backwater alcove
channel with large wood placements that would connect into the mainstem Wenatchee at the existing
smaller alcove.
The mainstem large wood would include small jams to enhance channel margin complexity and cover.
Some local pool scour and sediment sorting would also likely occur at the structures, but they would not
be large or stable enough to have a significant long‐term effect on geomorphic processes such as channel
migration. The primary purpose would be to address the RTT’s “channel structure and form” priority.
The primary fish benefit would be for rearing cover for juvenile salmonids and holding cover for adults.
The off‐channel alcove would increase juvenile off‐channel rearing habitat using excavation of a new
alcove area connected at a wide range of flow conditions. This component would help to increase the
availability of “peripheral and transitional habitat”. The primary fish benefit would be for overwintering
habitat for juvenile salmonids, but year‐round use would also be possible. The specific level of targeted
seasonal inundation will be further evaluated in later design stages. Large wood would be placed
throughout the backwater area to increase habitat complexity and cover.
Floodplain roughness wood would be placed along the disturbed temporary access corridor in the low
area between the created alcove and the existing high flow alcove to the south (Component 2 area). The
purpose of this roughness would be to add hydraulic roughness to the area of vegetation disturbance
from construction. Riparian enhancement using planting of native woody species would occur
throughout areas disturbed as part of construction activities.
Design Considerations
The potential for filling in of this backwater by sediments is believed to be relatively low due to the
upstream influence of Lake Wenatchee.
There is the potential for future beaver activity in the constructed off‐channel area. Based on the current
understanding of beaver activity and fish habitat, beaver use of the area is believed to be compatible with,
and will potentially enhance, fish use and habitat quality.
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The preferred route for access is being evaluated by the Yakama Nation. Pending landowner discussions,
access could occur via Highway 207 and using a temporary bridge to cross Nason Creek at the riffle at the
upstream end of the project area. There may be an alternate access route via the southwest side through
US Forest Service and/or State Park land. These potential access routes will be evaluated further in later
design stages.
The location and extent of excavation work will depend on the results of future wetlands assessment in
the area and consultation with permitting agencies.
COMPONENT 2: NASON LEFT BANK LARGE WOOD AND OFF‐CHANNEL ENHANCEMENT SITE A
Description and Potential Benefits
This component includes two primary elements: 1) large wood habitat cover along the river‐left bank of
lower Nason Creek, and 2) the expansion of an existing backwater alcove channel with large wood
placements that would connect into Nason Creek just upstream of the confluence.
The mainstem large wood would include small jams to enhance channel margin complexity and cover.
Some local pool scour and sediment sorting would also likely occur at the structures, but they would not
be large or stable enough to have a significant long‐term effect on geomorphic processes such as channel
migration. The primary purpose would be to address the RTT’s “channel structure and form” priority.
The primary fish benefit would be for rearing cover for juvenile salmonids and holding cover for adults.
The existing backwater alcove (see cover photo) would be expanded by greater than 600 feet and would
be enhanced using large wood placements. Expanding and enhancing the existing off‐channel alcove
would increase juvenile off‐channel rearing habitat by creating much greater off‐channel rearing capacity
and habitat quality at a wider range of flow conditions. This component would help to increase the
availability of “peripheral and transitional habitat”. The primary fish benefit would be for overwintering
habitat for juvenile salmonids, but year‐round use would also be possible. The specific level of targeted
seasonal inundation will be further evaluated in later design stages. Large wood would be placed
throughout the backwater area to increase habitat complexity and cover.
Floodplain roughness wood would be placed along the disturbed temporary access corridor at the
upstream end of the alcove. The purpose of this roughness would be to add hydraulic roughness to the
area of vegetation disturbance from construction. Riparian enhancement using planting of native woody
species would occur throughout areas disturbed as part of construction activities.
Design Considerations
There is potential for filling in of this backwater by Nason Creek sediments. The outlet, however, is
located at a lateral scour pool, which reduces the potential for bedload deposition (fines will still deposit).
The existing lower end of the alcove is connected at low flows, which suggests that periodic high flows
may scour this channel.
There is the potential for future beaver activity in the constructed off‐channel area. Based on the current
understanding of beaver activity and fish habitat, beaver use of the area is believed to be compatible with,
and will potentially enhance, fish use and habitat quality.
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The preferred route for access is being evaluated by the Yakama Nation. Pending landowner discussions,
access could occur via Highway 207 and using a temporary bridge to cross Nason Creek at the riffle at the
upstream end of the project area. There may be an alternate access route via the southwest side through
US Forest Service and/or State Park land. These potential access routes will be evaluated further in later
design stages.
The specific location and extent of excavation work will depend on the results of future wetlands
assessment in the area and consultation with permitting agencies.
COMPONENT 3: NASON LEFT BANK OFF‐CHANNEL ENHANCEMENT SITE B
Description and Potential Benefits
This component includes the expansion and enhancement of an existing high flow backwater alcove that
would connect into Nason Creek approximately 300 feet upstream of the confluence. The existing channel
scar would be expanded using excavation to deepen the alcove by approximately 150‐200 feet along its
length. Large wood would be added for habitat complexity and cover.
Expanding and enhancing the existing high flow alcove would increase juvenile off‐channel rearing
habitat by creating greater off‐channel rearing capacity and habitat quality at a wider range of flow
conditions. This component would help to increase the availability of “peripheral and transitional
habitat”. The primary fish benefit would be for overwintering habitat for juvenile salmonids, but year‐
round use would also be possible. The specific level of targeted seasonal inundation will be further
evaluated in later design stages.
Floodplain roughness wood could potentially be placed along the disturbed temporary access corridor at
the upstream end of the alcove. The purpose of this roughness would be to add hydraulic roughness to
the area of vegetation disturbance from construction. Riparian enhancement using planting of native
woody species would occur throughout areas disturbed as part of construction activities.
Design Considerations
There is potential for filling in of this backwater by Nason Creek sediments. The outlet is located at the
downstream end of an existing gravel point bar. This area will need to be further evaluated for the
potential for filling with bedload.
There is the potential for future beaver activity in the constructed off‐channel area. Based on the current
understanding of beaver activity and fish habitat, beaver use of the area is believed to be compatible with,
and will potentially enhance, fish use and habitat quality.
The preferred route for access is being evaluated by the Yakama Nation. Pending landowner discussions,
access could occur via Highway 207 and using a temporary bridge to cross Nason Creek at the riffle at the
upstream end of the project area. There may be an alternate access route via the southwest side through
US Forest Service and/or State Park land. These potential access routes will be evaluated further in later
design stages.
The specific location and extent of excavation work will depend on the results of future wetlands
assessment in the area and consultation with permitting agencies.
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COMPONENT 4: NASON RIGHT BANK LARGE WOOD AND SIDE‐CHANNEL ENHANCEMENT
Description and Potential Benefits
This component includes two primary elements: 1) large wood habitat cover along the river‐right bank of
lower Nason Creek, and 2) the creation of flow‐through side‐channel habitat.
The large wood component would include small jams along approximately 400 feet of bank to enhance
channel margin complexity and cover. Some local pool scour and sediment sorting would also likely
occur at the structures, but they would not be large or stable enough to have a significant long‐term effect
on geomorphic processes such as channel migration. The primary purpose would be to address the RTT’s
“channel structure and form” priority. The primary fish benefit would be for rearing cover for juvenile
salmonids and holding cover for adults.
Side‐channel enhancement would occur using excavation in an existing high flow channel scar that is
approximately 550 feet long. The channel would originate on Nason Creek approximately 250 feet
upstream of the confluence and would flow into the mainstem Wenatchee approximately 200 feet
upstream of the Hwy 207 Bridge. The side‐channel would increase juvenile off‐channel rearing habitat
and would also be capable of supporting steelhead spawning. This component would help to increase the
availability of “peripheral and transitional habitat”. The specific level of targeted seasonal
inundation/flow will be further evaluated in later design stages. Large wood would be placed throughout
the side‐channel to increase habitat complexity, cover, sediment sorting, and pool scour. A bar apex jam
could potentially be constructed at the inlet to help divert and maintain the flow‐split. This will be
evaluated further in later stages of design.
Floodplain roughness wood would be placed along the bar in several locations adjacent to the side‐
channel to encourage flow within the side‐channel and to restore roughness that would historically have
been present along the gravel bars. Riparian enhancement using planting of native woody species would
occur throughout areas disturbed as part of construction activities.
Design Considerations
In general, there would be risk of filling or other channel adjustment to this side‐channel. This is due to
the inherent risks of working within a depositional fan environment. The risks are greater with a flow‐
through side‐channel since bedload could be entrained into the channel entrance. Measures would be
taken to limit the filling risk to the extent possible (i.e. by adjusting the angle, invert elevation, and size of
the inlet), but there would still remain some risk nonetheless. The greatest risk of filling would occur as a
result of alluvial deposits following a large flood event on Nason Creek. Excavating this side channel at
the downstream end may allow it to function as a backwater even if the upstream end is cut off by
transported bed material.
The preferred route for access is being evaluated by the Yakama Nation. Access is likely to occur off of
Hwy 207 just south of the bridge across the Wenatchee.
The location and extent of excavation work will depend on the results of future wetlands assessment in
the area and consultation with permitting agencies.
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References Inter‐Fluve Inc. 2012. Upper Wenatchee River Stream Corridor Assessment and Habitat Restoration
Strategy. Prepared for Yakama Nation Fisheries, Upper Columbia Habitat Restoration Project,
Toppenish, WA.
Northwest Power and Conservation Council (NWPCC). 2004. Wenatchee Subbasin Plan.
U.S. Bureau of Reclamation (USBR). 2008. Nason Creek Tributary Assessment, Chelan County, WA. USDI
USBR Technical Service Center, Denver, CO and Pacific Northwest Regional Office, Boise, Idaho.
Upper Columbia Regional Technical Team (UCRTT). 2014. A Biological strategy to protect and restore
salmonid habitat in Upper Columbia Region (revised). A Report to the Upper Columbia Salmon
Recovery Board from the Upper Columbia Regional Technical Team.
Upper Columbia Salmon Recovery Board (UCSRB). 2007. Upper Columbia salmon and Steelhead
recovery plan: Upper Columbia Salmon Recovery Board, Wenatchee, Washington, 300 pp. Web site:
http://www.ucsrb.com/plan.asp.
Watershed Sciences, Inc. 2007. LiDAR remote sensing data collection: upper & lower Okanogan River,
Methow River, Lake Roosevelt, Wenatchee River and John Day River Study Areas. Prepared for:
Puget Sound LiDAR Consortium, Seattle, WA.
Appendix A
HEC-‐RAS Results Wenatchee River - Nason Confluence Project
Nason
1400.13947.63
754.01666.2
530.56
340.89
Na
son_
a
t_confl
Wenatchee_us
1535.45
1382.961112.13
Wena t chee
Wenatchee_ds
833.48
653.13508.7
392.97
259.66
42.38
Wena t chee
Nason_Confl
0 200 400 600 800 1000 1200 1400 16001860
1865
1870
1875
1880
1885
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015
Main Channel Distance (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
LOB
ROB
259.
66
392.
97
508.
7
653.
13
833.
48
1112
.13
1272
.04
1382
.96
1535
.45
Wenatchee Wenatchee_ds Wenatchee Wenatchee_us
0 500 1000 1500 2000 25001860
1865
1870
1875
1880
1885
1890
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015
Main Channel Distance (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
LOB
ROB
259.
66
392.
97
508.
7
653.
13
833.
48
340.
89
530.
56
666.
2
754.
01
833.
23
947.
63
1078
.7
1273
.76
1400
.13
Wenatchee Wenatchee_ds Nason_at_confl Nason
0 100 200 300 400 5001872
1874
1876
1878
1880
1882
1884
1886
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Nason_at_confl Reach = Nason RS = 1400.13
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038 .06
0 100 200 300 400 5001872
1874
1876
1878
1880
1882
1884
1886
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Nason_at_confl Reach = Nason RS = 1273.76
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038 .06
0 100 200 300 400 500 6001872
1874
1876
1878
1880
1882
1884
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Nason_at_confl Reach = Nason RS = 1078.7
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038 .06
0 100 200 300 400 500 600 7001872
1874
1876
1878
1880
1882
1884
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Nason_at_confl Reach = Nason RS = 947.63
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038 .06
0 200 400 600 8001870
1872
1874
1876
1878
1880
1882
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Nason_at_confl Reach = Nason RS = 833.23
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038 .06
0 200 400 600 800 10001870
1872
1874
1876
1878
1880
1882
1884
1886
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Nason_at_confl Reach = Nason RS = 754.01
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038 .06
0 200 400 600 800 10001870
1872
1874
1876
1878
1880
1882
1884
1886
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Nason_at_confl Reach = Nason RS = 666.2
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038 .06
0 200 400 600 800 1000 12001870
1880
1890
1900
1910
1920
1930
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Nason_at_confl Reach = Nason RS = 530.56
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038 .06
0 200 400 600 800 1000 12001868
1870
1872
1874
1876
1878
1880
1882
1884
1886
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Nason_at_confl Reach = Nason RS = 340.89
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038 .06
0 100 200 300 400 500 600 7001860
1870
1880
1890
1900
1910
1920
1930
1940
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Wenatchee Reach = Wenatchee_us RS = 1535.45
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038 .06
0 100 200 300 400 500 600 700 8001870
1875
1880
1885
1890
1895
1900
1905
1910
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Wenatchee Reach = Wenatchee_us RS = 1382.96
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038 .06
0 100 200 300 400 500 600 7001865
1870
1875
1880
1885
1890
1895
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Wenatchee Reach = Wenatchee_us RS = 1272.04
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038 .06
0 100 200 300 400 500 600 7001865
1870
1875
1880
1885
1890
1895
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Wenatchee Reach = Wenatchee_us RS = 1112.13
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038
0 100 200 300 400 500 6001865
1870
1875
1880
1885
1890
1895
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Wenatchee Reach = Wenatchee_ds RS = 833.48
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038 .06
0 100 200 300 400 5001865
1870
1875
1880
1885
1890
1895
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Wenatchee Reach = Wenatchee_ds RS = 653.13
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038 .06
0 100 200 300 400 5001865
1870
1875
1880
1885
1890
1895
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Wenatchee Reach = Wenatchee_ds RS = 508.7
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038 .06
0 100 200 300 400 500 6001860
1865
1870
1875
1880
1885
1890
1895
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Wenatchee Reach = Wenatchee_ds RS = 392.97
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038 .06
0 100 200 300 400 5001865
1870
1875
1880
1885
1890
1895
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Wenatchee Reach = Wenatchee_ds RS = 259.66
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038 .06
0 100 200 300 400 5001865
1870
1875
1880
1885
1890
1895
1900
Nason-Confl Plan: NasonCnfl_Ex 6/27/2015 River = Wenatchee Reach = Wenatchee_ds RS = 42.38
Station (ft)
Ele
vatio
n (f
t)
Legend
WS 100yr
WS 50yr
WS 25yr
WS 10yr
WS 5yr
WS 2yr
WS 5000cfs
WS 2000cfs
WS 1000cfs
WS 468cfs
Ground
Bank Sta
.06 .038 .06
HEC-RAS Plan: Existing
River Reach River Sta Profile Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl Shear Chan
(cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) (lb/sq ft)
Wenatchee Wenatchee_us 1535.45 468cfs 47.00 1867.07 1871.58 1871.58 0.000006 0.13 373.54 243.92 0.02 0.00
Wenatchee Wenatchee_us 1535.45 1000cfs 100.00 1867.07 1872.13 1872.13 0.000011 0.19 519.07 280.03 0.02 0.00
Wenatchee Wenatchee_us 1535.45 2000cfs 200.00 1867.07 1872.89 1872.89 0.000014 0.27 735.66 288.91 0.03 0.00
Wenatchee Wenatchee_us 1535.45 5000cfs 500.00 1867.07 1874.72 1874.72 0.000015 0.39 1276.12 299.44 0.03 0.00
Wenatchee Wenatchee_us 1535.45 2yr 908.00 1867.07 1876.17 1876.18 0.000019 0.53 1715.64 305.71 0.04 0.01
Wenatchee Wenatchee_us 1535.45 5yr 1391.00 1867.07 1877.47 1877.47 0.000022 0.66 2114.73 311.42 0.04 0.01
Wenatchee Wenatchee_us 1535.45 10yr 1775.00 1867.07 1878.35 1878.36 0.000024 0.74 2392.48 317.14 0.05 0.01
Wenatchee Wenatchee_us 1535.45 25yr 2340.00 1867.07 1879.50 1879.52 0.000026 0.85 2763.42 327.01 0.05 0.01
Wenatchee Wenatchee_us 1535.45 50yr 2822.00 1867.07 1880.39 1880.40 0.000028 0.93 3055.76 333.52 0.05 0.02
Wenatchee Wenatchee_us 1535.45 100yr 3361.00 1867.07 1881.26 1881.27 0.000029 1.02 3346.97 338.17 0.06 0.02
Wenatchee Wenatchee_us 1382.96 468cfs 47.00 1870.35 1871.58 1871.58 0.000182 0.36 130.92 231.22 0.08 0.01
Wenatchee Wenatchee_us 1382.96 1000cfs 100.00 1870.35 1872.12 1872.13 0.000107 0.36 281.11 338.17 0.07 0.01
Wenatchee Wenatchee_us 1382.96 2000cfs 200.00 1870.35 1872.88 1872.88 0.000054 0.36 550.84 384.38 0.05 0.00
Wenatchee Wenatchee_us 1382.96 5000cfs 500.00 1870.35 1874.72 1874.72 0.000022 0.38 1304.73 424.57 0.04 0.00
Wenatchee Wenatchee_us 1382.96 2yr 908.00 1870.35 1876.17 1876.17 0.000021 0.47 1945.78 460.37 0.04 0.01
Wenatchee Wenatchee_us 1382.96 5yr 1391.00 1870.35 1877.46 1877.47 0.000020 0.55 2545.01 465.32 0.04 0.01
Wenatchee Wenatchee_us 1382.96 10yr 1775.00 1870.35 1878.35 1878.36 0.000020 0.60 2958.41 469.10 0.04 0.01
Wenatchee Wenatchee_us 1382.96 25yr 2340.00 1870.35 1879.50 1879.51 0.000020 0.67 3503.47 475.55 0.04 0.01
Wenatchee Wenatchee_us 1382.96 50yr 2822.00 1870.35 1880.39 1880.40 0.000020 0.72 3926.07 480.19 0.04 0.01
Wenatchee Wenatchee_us 1382.96 100yr 3361.00 1870.35 1881.26 1881.27 0.000021 0.78 4345.02 484.86 0.05 0.01
Wenatchee Wenatchee_us 1272.04 468cfs 47.00 1869.72 1871.56 1871.56 0.000202 0.34 138.47 288.20 0.09 0.01
Wenatchee Wenatchee_us 1272.04 1000cfs 100.00 1869.72 1872.11 1872.12 0.000077 0.31 326.25 382.95 0.06 0.00
Wenatchee Wenatchee_us 1272.04 2000cfs 200.00 1869.72 1872.88 1872.88 0.000037 0.32 627.48 402.82 0.05 0.00
Wenatchee Wenatchee_us 1272.04 5000cfs 500.00 1869.72 1874.72 1874.72 0.000018 0.33 1501.36 529.11 0.03 0.00
Wenatchee Wenatchee_us 1272.04 2yr 908.00 1869.72 1876.17 1876.17 0.000015 0.40 2275.20 535.71 0.03 0.00
Wenatchee Wenatchee_us 1272.04 5yr 1391.00 1869.72 1877.46 1877.47 0.000015 0.47 2977.69 552.40 0.04 0.01
Wenatchee Wenatchee_us 1272.04 10yr 1775.00 1869.72 1878.35 1878.35 0.000015 0.51 3467.71 554.47 0.04 0.01
Wenatchee Wenatchee_us 1272.04 25yr 2340.00 1869.72 1879.50 1879.51 0.000015 0.57 4109.15 556.99 0.04 0.01
Wenatchee Wenatchee_us 1272.04 50yr 2822.00 1869.72 1880.39 1880.39 0.000015 0.62 4602.66 558.96 0.04 0.01
Wenatchee Wenatchee_us 1272.04 100yr 3361.00 1869.72 1881.26 1881.26 0.000015 0.67 5089.02 560.98 0.04 0.01
Wenatchee Wenatchee_us 1112.13 468cfs 47.00 1869.53 1871.55 1871.55 0.000021 0.14 335.67 492.87 0.03 0.00
Wenatchee Wenatchee_us 1112.13 1000cfs 100.00 1869.53 1872.11 1872.11 0.000013 0.16 623.55 517.51 0.03 0.00
Wenatchee Wenatchee_us 1112.13 2000cfs 200.00 1869.53 1872.88 1872.88 0.000010 0.20 1020.67 520.94 0.02 0.00
Wenatchee Wenatchee_us 1112.13 5000cfs 500.00 1869.53 1874.71 1874.72 0.000007 0.25 1984.33 527.07 0.02 0.00
Wenatchee Wenatchee_us 1112.13 2yr 908.00 1869.53 1876.17 1876.17 0.000008 0.33 2754.29 532.67 0.03 0.00
Wenatchee Wenatchee_us 1112.13 5yr 1391.00 1869.53 1877.46 1877.47 0.000009 0.40 3446.89 537.13 0.03 0.00
Wenatchee Wenatchee_us 1112.13 10yr 1775.00 1869.53 1878.35 1878.35 0.000010 0.45 3923.75 539.95 0.03 0.00
Wenatchee Wenatchee_us 1112.13 25yr 2340.00 1869.53 1879.50 1879.51 0.000010 0.52 4548.70 542.91 0.03 0.01
Wenatchee Wenatchee_us 1112.13 50yr 2822.00 1869.53 1880.39 1880.39 0.000011 0.56 5029.84 545.20 0.03 0.01
Wenatchee Wenatchee_us 1112.13 100yr 3361.00 1869.53 1881.26 1881.26 0.000011 0.61 5504.30 547.53 0.03 0.01
Wenatchee Wenatchee_ds 833.48 468cfs 468.00 1868.94 1871.28 1871.34 0.002932 1.94 241.79 274.35 0.36 0.16
Wenatchee Wenatchee_ds 833.48 1000cfs 1000.00 1868.94 1871.86 1871.95 0.002635 2.47 405.50 294.50 0.37 0.22
Wenatchee Wenatchee_ds 833.48 2000cfs 2000.00 1868.94 1872.57 1872.72 0.002855 3.18 628.53 330.29 0.41 0.33
Wenatchee Wenatchee_ds 833.48 5000cfs 5000.00 1868.94 1874.34 1874.60 0.002036 4.03 1239.65 354.16 0.38 0.44
Wenatchee Wenatchee_ds 833.48 2yr 7725.00 1868.94 1875.76 1876.06 0.001604 4.41 1761.41 379.80 0.36 0.47
Wenatchee Wenatchee_ds 833.48 5yr 10473.00 1868.94 1877.02 1877.36 0.001371 4.71 2248.74 400.07 0.34 0.50
Wenatchee Wenatchee_ds 833.48 10yr 12559.00 1868.94 1877.87 1878.25 0.001253 4.93 2592.56 403.34 0.33 0.53
Wenatchee Wenatchee_ds 833.48 25yr 15520.00 1868.94 1878.98 1879.40 0.001148 5.22 3042.87 407.46 0.33 0.56
Wenatchee Wenatchee_ds 833.48 50yr 17978.00 1868.94 1879.83 1880.29 0.001092 5.45 3389.39 410.69 0.32 0.59
Wenatchee Wenatchee_ds 833.48 100yr 20665.00 1868.94 1880.65 1881.15 0.001066 5.71 3727.80 413.66 0.32 0.63
Wenatchee Wenatchee_ds 653.13 468cfs 468.00 1868.28 1870.69 1870.16 1870.77 0.003398 2.21 211.84 219.10 0.40 0.20
Wenatchee Wenatchee_ds 653.13 1000cfs 1000.00 1868.28 1871.14 1870.56 1871.29 0.005191 3.13 319.39 268.95 0.51 0.38
Wenatchee Wenatchee_ds 653.13 2000cfs 2000.00 1868.28 1871.84 1872.08 0.004499 3.93 508.99 272.79 0.51 0.52
Wenatchee Wenatchee_ds 653.13 5000cfs 5000.00 1868.28 1873.83 1874.17 0.002579 4.71 1061.91 282.77 0.43 0.59
Wenatchee Wenatchee_ds 653.13 2yr 7725.00 1868.28 1875.30 1875.72 0.002108 5.21 1482.70 295.53 0.41 0.65
Wenatchee Wenatchee_ds 653.13 5yr 10473.00 1868.28 1876.57 1877.06 0.001873 5.63 1881.61 333.74 0.40 0.71
Wenatchee Wenatchee_ds 653.13 10yr 12559.00 1868.28 1877.43 1877.97 0.001743 5.92 2168.82 335.09 0.39 0.75
Wenatchee Wenatchee_ds 653.13 25yr 15520.00 1868.28 1878.53 1879.14 0.001630 6.30 2539.22 336.54 0.39 0.81
Wenatchee Wenatchee_ds 653.13 50yr 17978.00 1868.28 1879.36 1880.03 0.001574 6.60 2820.54 337.73 0.39 0.86
Wenatchee Wenatchee_ds 653.13 100yr 20665.00 1868.28 1880.16 1880.90 0.001560 6.95 3089.80 338.90 0.39 0.93
Wenatchee Wenatchee_ds 508.7 468cfs 468.00 1867.98 1869.38 1869.38 1869.69 0.026461 4.44 105.36 180.41 1.02 0.96
Wenatchee Wenatchee_ds 508.7 1000cfs 1000.00 1867.98 1870.14 1870.38 0.007764 3.90 256.12 212.10 0.63 0.58
Wenatchee Wenatchee_ds 508.7 2000cfs 2000.00 1867.98 1871.23 1871.49 0.003687 4.06 492.60 219.76 0.48 0.51
Wenatchee Wenatchee_ds 508.7 5000cfs 5000.00 1867.98 1873.40 1873.80 0.002503 5.10 981.34 232.16 0.44 0.66
Wenatchee Wenatchee_ds 508.7 2yr 7725.00 1867.98 1874.87 1875.39 0.002283 5.82 1327.25 239.48 0.44 0.78
Wenatchee Wenatchee_ds 508.7 5yr 10473.00 1867.98 1876.11 1876.75 0.002160 6.43 1631.17 260.17 0.44 0.90
Wenatchee Wenatchee_ds 508.7 10yr 12559.00 1867.98 1876.94 1877.67 0.002097 6.85 1852.56 271.11 0.44 0.98
Wenatchee Wenatchee_ds 508.7 25yr 15520.00 1867.98 1878.01 1878.85 0.002049 7.39 2141.85 273.25 0.44 1.09
Wenatchee Wenatchee_ds 508.7 50yr 17978.00 1867.98 1878.80 1879.74 0.002034 7.81 2360.41 274.94 0.45 1.18
Wenatchee Wenatchee_ds 508.7 100yr 20665.00 1867.98 1879.55 1880.61 0.002074 8.30 2565.08 276.54 0.46 1.30
Wenatchee Wenatchee_ds 392.97 468cfs 468.00 1862.52 1869.30 1869.31 0.000173 1.05 445.54 151.08 0.11 0.03
Wenatchee Wenatchee_ds 392.97 1000cfs 1000.00 1862.52 1870.16 1870.21 0.000342 1.73 577.56 153.86 0.16 0.08
Wenatchee Wenatchee_ds 392.97 2000cfs 2000.00 1862.52 1871.19 1871.30 0.000628 2.71 736.96 157.29 0.22 0.18
Wenatchee Wenatchee_ds 392.97 5000cfs 5000.00 1862.52 1873.25 1873.59 0.001224 4.68 1068.15 164.89 0.32 0.48
Wenatchee Wenatchee_ds 392.97 2yr 7725.00 1862.52 1874.62 1875.17 0.001597 5.95 1298.21 170.17 0.38 0.74
Wenatchee Wenatchee_ds 392.97 5yr 10473.00 1862.52 1875.76 1876.51 0.001844 6.97 1558.86 260.92 0.42 0.97
Wenatchee Wenatchee_ds 392.97 10yr 12559.00 1862.52 1876.54 1877.42 0.001954 7.60 1768.02 284.02 0.44 1.12
Wenatchee Wenatchee_ds 392.97 25yr 15520.00 1862.52 1877.53 1878.59 0.002077 8.38 2081.43 333.38 0.46 1.32
Wenatchee Wenatchee_ds 392.97 50yr 17978.00 1862.52 1878.32 1879.48 0.002109 8.86 2344.03 334.30 0.47 1.44
Wenatchee Wenatchee_ds 392.97 100yr 20665.00 1862.52 1879.05 1880.34 0.002186 9.40 2586.98 335.10 0.48 1.59
Wenatchee Wenatchee_ds 259.66 468cfs 468.00 1865.34 1869.13 1868.56 1869.24 0.003841 2.72 171.89 142.85 0.44 0.29
Wenatchee Wenatchee_ds 259.66 1000cfs 1000.00 1865.34 1869.90 1870.09 0.003470 3.50 285.37 150.31 0.45 0.41
Wenatchee Wenatchee_ds 259.66 2000cfs 2000.00 1865.34 1870.74 1871.10 0.004239 4.81 415.42 157.71 0.52 0.69
Wenatchee Wenatchee_ds 259.66 5000cfs 5000.00 1865.34 1872.42 1873.24 0.005342 7.26 688.28 167.17 0.63 1.35
Wenatchee Wenatchee_ds 259.66 2yr 7725.00 1865.34 1873.53 1874.73 0.005968 8.81 876.85 172.97 0.69 1.86
Wenatchee Wenatchee_ds 259.66 5yr 10473.00 1865.34 1874.39 1876.00 0.006587 10.19 1028.49 181.94 0.74 2.37
Wenatchee Wenatchee_ds 259.66 10yr 12559.00 1865.34 1874.94 1873.91 1876.87 0.007031 11.17 1139.86 223.38 0.78 2.76
Wenatchee Wenatchee_ds 259.66 25yr 15520.00 1865.34 1875.62 1874.82 1877.98 0.007576 12.40 1310.15 268.20 0.82 3.29
Wenatchee Wenatchee_ds 259.66 50yr 17978.00 1865.34 1876.12 1875.58 1878.84 0.007973 13.32 1455.84 319.66 0.85 3.71
Wenatchee Wenatchee_ds 259.66 100yr 20665.00 1865.34 1876.71 1876.59 1879.67 0.007984 14.00 1643.69 322.36 0.86 4.00
HEC-RAS Plan: Existing (Continued)
River Reach River Sta Profile Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl Shear Chan
(cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) (lb/sq ft)
Wenatchee Wenatchee_ds 42.38 468cfs 468.00 1866.16 1868.15 1867.67 1868.29 0.005005 3.04 153.85 133.20 0.50 0.36
Wenatchee Wenatchee_ds 42.38 1000cfs 1000.00 1866.16 1868.99 1868.20 1869.19 0.005004 3.56 281.04 191.97 0.52 0.46
Wenatchee Wenatchee_ds 42.38 2000cfs 2000.00 1866.16 1869.77 1869.02 1870.10 0.005003 4.62 433.27 200.04 0.55 0.67
Wenatchee Wenatchee_ds 42.38 5000cfs 5000.00 1866.16 1871.42 1870.30 1872.07 0.005002 6.47 772.81 214.60 0.60 1.12
Wenatchee Wenatchee_ds 42.38 2yr 7725.00 1866.16 1872.57 1871.20 1873.45 0.005002 7.51 1028.67 228.22 0.62 1.40
Wenatchee Wenatchee_ds 42.38 5yr 10473.00 1866.16 1873.51 1872.04 1874.61 0.005000 8.39 1249.23 240.02 0.64 1.65
Wenatchee Wenatchee_ds 42.38 10yr 12559.00 1866.16 1874.12 1872.62 1875.39 0.005005 9.03 1401.54 281.12 0.65 1.84
Wenatchee Wenatchee_ds 42.38 25yr 15520.00 1866.16 1874.91 1873.33 1876.40 0.005002 9.80 1626.01 290.16 0.67 2.08
Wenatchee Wenatchee_ds 42.38 50yr 17978.00 1866.16 1875.51 1873.86 1877.16 0.005001 10.38 1803.67 301.40 0.68 2.27
Wenatchee Wenatchee_ds 42.38 100yr 20665.00 1866.16 1876.13 1874.50 1877.97 0.005002 10.96 2010.10 373.28 0.69 2.46
Nason_at_confl Nason 1400.13 468cfs 421.00 1873.86 1876.17 1876.30 0.002529 2.92 155.31 95.56 0.38 0.29
Nason_at_confl Nason 1400.13 1000cfs 900.00 1873.86 1877.20 1877.41 0.002640 3.80 262.32 113.31 0.41 0.43
Nason_at_confl Nason 1400.13 2000cfs 1800.00 1873.86 1878.46 1878.78 0.002974 4.78 423.30 139.34 0.46 0.62
Nason_at_confl Nason 1400.13 5000cfs 4500.00 1873.86 1880.47 1881.18 0.003711 7.22 804.78 291.85 0.55 1.22
Nason_at_confl Nason 1400.13 2yr 6817.00 1873.86 1881.67 1882.54 0.003707 8.26 1226.82 377.95 0.57 1.50
Nason_at_confl Nason 1400.13 5yr 9082.00 1873.86 1883.01 1883.75 0.002744 8.04 1733.68 381.16 0.50 1.33
Nason_at_confl Nason 1400.13 10yr 10784.00 1873.86 1883.58 1884.39 0.002803 8.52 1952.43 382.68 0.52 1.46
Nason_at_confl Nason 1400.13 25yr 13180.00 1873.86 1884.50 1885.34 0.002635 8.85 2306.33 387.39 0.51 1.52
Nason_at_confl Nason 1400.13 50yr 15156.00 1873.86 1885.17 1886.06 0.002604 9.21 2568.20 402.44 0.51 1.61
Nason_at_confl Nason 1400.13 100yr 17304.00 1873.86 1885.23 1886.37 0.003298 10.40 2594.38 402.44 0.58 2.05
Nason_at_confl Nason 1273.76 468cfs 421.00 1873.00 1876.00 1876.08 0.001153 2.31 194.46 90.93 0.27 0.16
Nason_at_confl Nason 1273.76 1000cfs 900.00 1873.00 1876.96 1877.13 0.001750 3.36 293.04 111.13 0.34 0.32
Nason_at_confl Nason 1273.76 2000cfs 1800.00 1873.00 1878.12 1878.45 0.002445 4.71 435.38 141.68 0.42 0.58
Nason_at_confl Nason 1273.76 5000cfs 4500.00 1873.00 1879.91 1880.71 0.003827 7.59 703.49 183.43 0.56 1.33
Nason_at_confl Nason 1273.76 2yr 6817.00 1873.00 1880.79 1879.51 1881.98 0.004966 9.51 943.33 292.93 0.66 1.99
Nason_at_confl Nason 1273.76 5yr 9082.00 1873.00 1881.42 1880.84 1883.16 0.006464 11.54 1156.12 363.03 0.76 2.84
Nason_at_confl Nason 1273.76 10yr 10784.00 1873.00 1881.88 1881.88 1883.78 0.006739 12.29 1326.96 379.69 0.78 3.15
Nason_at_confl Nason 1273.76 25yr 13180.00 1873.00 1882.11 1880.75 1884.64 0.008785 14.30 1416.07 402.25 0.90 4.23
Nason_at_confl Nason 1273.76 50yr 15156.00 1873.00 1882.33 1880.92 1885.30 0.010114 15.64 1505.56 403.26 0.97 5.01
Nason_at_confl Nason 1273.76 100yr 17304.00 1873.00 1883.41 1883.41 1885.70 0.007107 14.25 1943.55 409.28 0.83 3.99
Nason_at_confl Nason 1078.7 468cfs 421.00 1873.13 1875.53 1875.69 0.004167 3.14 133.93 95.06 0.47 0.36
Nason_at_confl Nason 1078.7 1000cfs 900.00 1873.13 1876.33 1876.60 0.004881 4.15 217.12 114.58 0.53 0.57
Nason_at_confl Nason 1078.7 2000cfs 1800.00 1873.13 1877.36 1877.78 0.005250 5.16 349.49 144.39 0.58 0.81
Nason_at_confl Nason 1078.7 5000cfs 4500.00 1873.13 1879.09 1879.82 0.005734 6.98 710.06 263.17 0.64 1.30
Nason_at_confl Nason 1078.7 2yr 6817.00 1873.13 1879.83 1879.22 1880.89 0.006722 8.54 937.47 331.07 0.72 1.82
Nason_at_confl Nason 1078.7 5yr 9082.00 1873.13 1880.36 1880.10 1881.77 0.007845 9.95 1160.24 479.48 0.79 2.38
Nason_at_confl Nason 1078.7 10yr 10784.00 1873.13 1880.72 1880.72 1882.29 0.008134 10.63 1341.73 515.08 0.81 2.66
Nason_at_confl Nason 1078.7 25yr 13180.00 1873.13 1881.31 1881.31 1882.92 0.007650 11.05 1655.76 549.17 0.80 2.77
Nason_at_confl Nason 1078.7 50yr 15156.00 1873.13 1881.68 1881.68 1883.39 0.007706 11.55 1856.67 549.17 0.81 2.97
Nason_at_confl Nason 1078.7 100yr 17304.00 1873.13 1882.07 1882.02 1883.86 0.007625 11.96 2073.67 549.17 0.82 3.12
Nason_at_confl Nason 947.63 468cfs 421.00 1872.00 1874.93 1875.08 0.005107 3.16 133.13 107.21 0.50 0.38
Nason_at_confl Nason 947.63 1000cfs 900.00 1872.00 1875.61 1875.89 0.005881 4.28 210.43 119.33 0.57 0.63
Nason_at_confl Nason 947.63 2000cfs 1800.00 1872.00 1876.58 1877.02 0.006390 5.30 340.73 153.37 0.62 0.88
Nason_at_confl Nason 947.63 5000cfs 4500.00 1872.00 1878.56 1879.09 0.004930 5.97 863.30 382.07 0.58 0.99
Nason_at_confl Nason 947.63 2yr 6817.00 1872.00 1879.46 1880.09 0.004479 6.68 1236.86 468.04 0.57 1.14
Nason_at_confl Nason 947.63 5yr 9082.00 1872.00 1880.11 1880.85 0.004522 7.39 1566.23 636.20 0.59 1.33
Nason_at_confl Nason 947.63 10yr 10784.00 1872.00 1880.52 1881.33 0.004549 7.83 1830.47 644.84 0.60 1.45
Nason_at_confl Nason 947.63 25yr 13180.00 1872.00 1881.00 1881.91 0.004715 8.44 2139.36 653.75 0.62 1.64
Nason_at_confl Nason 947.63 50yr 15156.00 1872.00 1881.45 1882.39 0.004504 8.68 2438.02 659.88 0.61 1.69
Nason_at_confl Nason 947.63 100yr 17304.00 1872.00 1882.03 1882.96 0.004082 8.77 2820.04 665.22 0.59 1.68
Nason_at_confl Nason 833.23 468cfs 421.00 1871.34 1874.34 1874.48 0.005450 3.09 141.16 133.19 0.52 0.38
Nason_at_confl Nason 833.23 1000cfs 900.00 1871.34 1875.02 1875.23 0.005474 3.79 248.69 173.16 0.54 0.51
Nason_at_confl Nason 833.23 2000cfs 1800.00 1871.34 1876.23 1876.48 0.003052 4.09 470.94 208.35 0.44 0.50
Nason_at_confl Nason 833.23 5000cfs 4500.00 1871.34 1878.26 1878.66 0.002695 5.33 1069.61 449.97 0.45 0.72
Nason_at_confl Nason 833.23 2yr 6817.00 1871.34 1879.20 1879.69 0.002664 6.05 1551.00 689.99 0.47 0.86
Nason_at_confl Nason 833.23 5yr 9082.00 1871.34 1879.89 1880.43 0.002694 6.61 2036.60 715.01 0.48 0.99
Nason_at_confl Nason 833.23 10yr 10784.00 1871.34 1880.32 1880.90 0.002751 7.00 2354.24 757.40 0.49 1.08
Nason_at_confl Nason 833.23 25yr 13180.00 1871.34 1880.77 1881.46 0.003071 7.73 2697.40 774.08 0.52 1.29
Nason_at_confl Nason 833.23 50yr 15156.00 1871.34 1881.28 1881.96 0.002858 7.83 3091.15 774.08 0.51 1.29
Nason_at_confl Nason 833.23 100yr 17304.00 1871.34 1881.92 1882.56 0.002488 7.73 3589.60 774.08 0.48 1.22
Nason_at_confl Nason 754.01 468cfs 421.00 1870.97 1873.56 1873.82 0.013820 4.08 103.17 121.64 0.78 0.72
Nason_at_confl Nason 754.01 1000cfs 900.00 1870.97 1874.61 1874.84 0.004398 3.84 234.09 127.60 0.50 0.50
Nason_at_confl Nason 754.01 2000cfs 1800.00 1870.97 1875.93 1876.23 0.002975 4.40 413.61 148.97 0.45 0.55
Nason_at_confl Nason 754.01 5000cfs 4500.00 1870.97 1877.94 1878.43 0.002786 5.92 1037.63 517.43 0.47 0.84
Nason_at_confl Nason 754.01 2yr 6817.00 1870.97 1878.99 1879.48 0.002456 6.32 1741.28 740.58 0.45 0.90
Nason_at_confl Nason 754.01 5yr 9082.00 1870.97 1879.73 1880.22 0.002338 6.66 2323.20 795.70 0.45 0.96
Nason_at_confl Nason 754.01 10yr 10784.00 1870.97 1880.17 1880.68 0.002341 6.95 2677.63 805.93 0.46 1.03
Nason_at_confl Nason 754.01 25yr 13180.00 1870.97 1880.63 1881.20 0.002529 7.53 3050.00 818.45 0.48 1.18
Nason_at_confl Nason 754.01 50yr 15156.00 1870.97 1881.15 1881.71 0.002373 7.62 3481.22 830.92 0.47 1.19
Nason_at_confl Nason 754.01 100yr 17304.00 1870.97 1881.81 1882.34 0.002107 7.57 4031.78 834.76 0.45 1.14
Nason_at_confl Nason 666.2 468cfs 421.00 1870.29 1873.42 1873.48 0.001375 2.12 202.01 121.19 0.28 0.15
Nason_at_confl Nason 666.2 1000cfs 900.00 1870.29 1874.50 1874.62 0.001276 2.75 345.24 143.86 0.29 0.22
Nason_at_confl Nason 666.2 2000cfs 1800.00 1870.29 1875.84 1876.03 0.001359 3.56 575.37 221.55 0.31 0.33
Nason_at_confl Nason 666.2 5000cfs 4500.00 1870.29 1877.83 1878.19 0.001742 5.26 1176.80 376.86 0.38 0.63
Nason_at_confl Nason 666.2 2yr 6817.00 1870.29 1878.73 1879.26 0.002246 6.55 1661.00 638.53 0.44 0.93
Nason_at_confl Nason 666.2 5yr 9082.00 1870.29 1879.34 1879.98 0.002543 7.39 2117.34 818.74 0.47 1.15
Nason_at_confl Nason 666.2 10yr 10784.00 1870.29 1879.75 1880.43 0.002675 7.84 2457.96 862.92 0.49 1.28
Nason_at_confl Nason 666.2 25yr 13180.00 1870.29 1880.16 1880.93 0.002981 8.56 2809.65 866.29 0.52 1.49
Nason_at_confl Nason 666.2 50yr 15156.00 1870.29 1880.79 1881.47 0.002581 8.36 3357.99 870.68 0.49 1.39
Nason_at_confl Nason 666.2 100yr 17304.00 1870.29 1881.55 1882.14 0.002135 8.03 4022.09 881.66 0.45 1.25
Nason_at_confl Nason 530.56 468cfs 421.00 1870.91 1873.24 1873.31 0.001162 2.12 199.64 101.16 0.26 0.15
Nason_at_confl Nason 530.56 1000cfs 900.00 1870.91 1874.31 1874.44 0.001312 2.92 329.62 168.41 0.30 0.24
Nason_at_confl Nason 530.56 2000cfs 1800.00 1870.91 1875.64 1875.84 0.001388 3.74 608.91 274.41 0.32 0.36
Nason_at_confl Nason 530.56 5000cfs 4500.00 1870.91 1877.63 1877.93 0.001621 5.02 1418.73 523.02 0.36 0.58
Nason_at_confl Nason 530.56 2yr 6817.00 1870.91 1878.48 1878.91 0.002103 6.25 2036.60 859.92 0.42 0.85
Nason_at_confl Nason 530.56 5yr 9082.00 1870.91 1879.13 1879.58 0.002146 6.71 2604.34 899.01 0.43 0.96
Nason_at_confl Nason 530.56 10yr 10784.00 1870.91 1879.55 1880.01 0.002161 6.99 2985.26 906.75 0.44 1.02
Nason_at_confl Nason 530.56 25yr 13180.00 1870.91 1879.94 1880.46 0.002419 7.63 3335.23 908.11 0.47 1.19
Nason_at_confl Nason 530.56 50yr 15156.00 1870.91 1880.62 1881.08 0.002006 7.33 3957.69 908.83 0.43 1.07
Nason_at_confl Nason 530.56 100yr 17304.00 1870.91 1881.42 1881.81 0.001617 6.97 4686.80 909.67 0.39 0.94
HEC-RAS Plan: Existing (Continued)
River Reach River Sta Profile Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl Shear Chan
(cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) (lb/sq ft)
Nason_at_confl Nason 340.89 468cfs 421.00 1869.58 1872.44 1872.06 1872.80 0.009436 4.79 87.82 61.57 0.71 0.84
Nason_at_confl Nason 340.89 1000cfs 900.00 1869.58 1872.95 1872.95 1873.75 0.018041 7.18 125.27 77.50 1.00 1.80
Nason_at_confl Nason 340.89 2000cfs 1800.00 1869.58 1873.95 1873.95 1875.11 0.016292 8.66 207.91 89.38 1.00 2.32
Nason_at_confl Nason 340.89 5000cfs 4500.00 1869.58 1876.21 1876.21 1877.25 0.010388 8.44 647.57 411.10 0.84 2.00
Nason_at_confl Nason 340.89 2yr 6817.00 1869.58 1876.97 1876.97 1878.13 0.009743 9.33 1005.22 533.42 0.84 2.29
Nason_at_confl Nason 340.89 5yr 9082.00 1869.58 1877.58 1877.58 1878.82 0.009079 9.94 1367.44 647.44 0.83 2.47
Nason_at_confl Nason 340.89 10yr 10784.00 1869.58 1877.95 1877.70 1879.26 0.008990 10.43 1617.17 711.39 0.84 2.65
Nason_at_confl Nason 340.89 25yr 13180.00 1869.58 1879.38 1879.97 0.003474 7.71 3074.49 1028.88 0.54 1.33
Nason_at_confl Nason 340.89 50yr 15156.00 1869.58 1880.31 1880.72 0.002201 6.73 4025.08 1031.15 0.44 0.97
Nason_at_confl Nason 340.89 100yr 17304.00 1869.58 1881.21 1881.54 0.001570 6.15 4958.52 1032.87 0.38 0.78
LOCATION MAPSTATE OF WASHINGTON
VICINITY MAP SITE MAP
501 Porway Avenue, Suite 101Hood River, OR 97031
541.386.9003www.interfluve.com
COVER SHEET, DRAWING LIST,AND LOCATION MAPS
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PreliminaryNot for Construction
IDAHO
BELLINGHAM
SEATTLE SPOKANE
PORTLAND
OREGON
ELLENSBURG
WENATCHEE
YAKIMA
LEAVENWORTH
EVERETT
Leavenworth
Coles CornerHwy 2
Skykomish
Lake Wenachee
Plain
Nason Creek
Wenatchee River
Wenatchee River
207
Happy ClownRestaurant
Lake WenatcheeVillage
HeadwatersSpirits andBrewing
Brae Burn Rd
State Park Rd
NF-660
5
4.0 mi. to
Cole's Corner
COORDINATES:LATITUDE 47° 48' 28" NLONGITUDE 120° 43' 01" W
SECTION 28, TOWNSHIP 27N, RANGE 17E
WATERBODY: NASON CREEK
TRIBUTARY OF: WENATCHEE RIVER
DRAWING LIST1 Cover Sheet, Drawing List, and Location Maps
2 Existing Conditions, Ownership, and Access
3 Proposed Conditions and Sheet Index
4 Wenatchee Mainstem Large Wood and Off-Channel Enhancement
5 Nason Left Bank Large Wood and Off-Channel Enhancement Site A
6 Nason Left Bank Off-Channel Enhancement Site B
7 Nason Right Bank Large Wood and Side-Channel Enhancement
8 LWM Typical Details
9 LWM Typical Details
NTS
Hwy
207
Unn
amed
Cam
pgro
und
Rd
PROJECT AREA
WENATCHEE RIVER - NASON CONFLUENCE PROJECTCONCEPTUAL DESIGN
PLAN
501 Porway Avenue, Suite 101Hood River, OR 97031
541.386.9003www.interfluve.com
EXISTING CONDITIONS,OWNERSHIP, AND ACCESS
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SCALE IN FEET
0 400200
Wenatchee River
Wenatchee River
Brae Burn Rd
Unnamed Campground Rd
Highway 207
LEGEND
Nason Creek
NOTE:POTENTIAL TEMPORARY ACCESSROUTES ARE PENDING FURTHEREVALUATION.
TEMPORARY CROSSING,LOCATION TO BE DETERMINED
PROPERTY LINES
LIMITS OF DISTURBANCE
EXISTING CHANNEL
EXISTING UNIMPROVED ROAD
TEMPORARY ACCESS ROAD
PLAN
501 Porway Avenue, Suite 101Hood River, OR 97031
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PROPOSED CONDITIONSAND SHEET INDEX
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SCALE IN FEET
0 400200
MARGIN WOOD ANDBACKWATER 1, SEE SHEET 4
BACKWATER 2, SEE SHEET 5
BACKWATER 3,SEE SHEET 6
SIDE CHANN
EL,SEE SHEET 7
Nason Creek
Wenatchee River
Wenatchee River
LEGENDPROPERTY LINES
LIMITS OF DISTURBANCE
EXISTING UNIMPROVED ROAD
TEMPORARY ACCESS ROAD
EXISTING CHANNEL
PROPOSED CHANNEL
PROPOSED LWM PLACEMENT
Brae Burn Rd
Unnamed Campground Rd
Highway 207
LONGITUDINAL PROFILE THROUGH BACKWATER CHANNEL 1
1870
1880
1870
1880
0+00 1+00 2+00 3+00 4+00 5+00 5+84
TIE IN TO EXISTING GRADETIE IN TO EXISTING GRADE
EXISTING GRADE
PROPOSED GRADE
PLAN VIEW OF BACKWATER CHANNEL 1
501 Porway Avenue, Suite 101Hood River, OR 97031
541.386.9003www.interfluve.com
WENATCHEE MAINSTEM LARGE WOODAND OFF-CHANNEL ENHANCEMENT
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SCALE IN FEET
0 12060
HABITAT COVER WOOD,TYP, SEE SHEET 9
BACKWATER HABITATWOOD, TYP, SEE SHEET 8
BACKWATERCHANNEL 1CENTERLINE
SCALE: 1" = 60'
SCAL
E: 1
" = 1
2'
5x VERTICAL EXAGGERATION
LEGENDEXISTING CONTOURS (1-FT INTERVAL)
PROPOSED CONTOURS (1-FT INTERVAL)
LIMITS OF DISTURBANCE
EXISTING CHANNEL
PROPOSED CHANNEL
PROPOSED CENTERLINE ALIGNMENT
EXISTING UNIMPROVED ROAD
TEMPORARY ACCESS ROAD
4+00
FLOODPLAIN ROUGHNESSWOOD, TYP, SEE SHEET 9
NOT TO SCALE41 TYPICAL CROSS SECTION
PROPOSED CHANNEL
NASON CREEK
WENATCHEE RIVER
LONGITUDINAL PROFILE THROUGH BACKWATER CHANNEL 2
1860
1870
1880
1860
1870
1880
0+00 1+00 2+00 3+00 4+00 5+00 6+00 7+00 8+00 9+00 9+33
PROPOSED GRADE
EXISTING GRADE
TIE IN TO EXISTING GRADETIE IN TO EXISTING GRADE
PLAN VIEW OF BACKWATER CHANNEL 2
501 Porway Avenue, Suite 101Hood River, OR 97031
541.386.9003www.interfluve.com
NASON LEFT BANK LARGE WOOD ANDOFF-CHANNEL ENHANCEMENT SITE A
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SCALE IN FEET
0 16080
BACKWATER 2, SEEPROFILE BELOW
BACKWATER HABITATWOOD, TYP, SEE SHEET 8
SCALE: 1" = 80'
SCAL
E: 1
" = 1
6'
5x VERTICAL EXAGGERATION
LEGEND
FLOODPLAIN ROUGHNESSWOOD, TYP, SEE SHEET 9
NASON CREEK
NASON CREEK
NOT TO SCALE51 TYPICAL CROSS SECTION
PROPOSED CHANNEL
WEN
ATCH
EE R
IVER
EXISTING CONTOURS (1-FT INTERVAL)
PROPOSED CONTOURS (1-FT INTERVAL)
LIMITS OF DISTURBANCE
EXISTING CHANNEL
PROPOSED CHANNEL
PROPOSED CENTERLINE ALIGNMENT
TEMPORARY ACCESS ROAD
4+00
LONGITUDINAL PROFILE THROUGH BACKWATER CHANNEL 3
1870
1880
1870
1880
0+00 1+00 2+00 2+95
EXISTING GRADE
TIE IN TO EXISTING GRADETIE IN TO EXISTING GRADE
PROPOSED GRADE
PLAN VIEW OF BACKWATER CHANNEL 3
501 Porway Avenue, Suite 101Hood River, OR 97031
541.386.9003www.interfluve.com
NASON LEFT BANK OFF-CHANNELENHANCEMENT SITE B
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SCALE IN FEET
0 6030
BACKWATER 3, SEE PROFILE BELOW
BACKWATER HABITATWOOD, SEE SHEET 8
SCALE: 1" = 30'
SCAL
E: 1
" = 6
'
5x VERTICAL EXAGGERATION
LEGEND
NOT TO SCALE61 TYPICAL CROSS SECTION
PROPOSED CHANNEL
NASON CREEK
EXISTING CONTOURS (1-FT INTERVAL)
PROPOSED CONTOURS (1-FT INTERVAL)
LIMITS OF DISTURBANCE
EXISTING CHANNEL
PROPOSED CHANNEL
TEMPORARY ACCESS ROAD
4+00
LONGITUDINAL PROFILE THROUGH SIDE CHANNEL
1860
1870
1880
1860
1870
1880
0+00 1+00 2+00 3+00 4+00 5+00 6+00 6+41
TIE IN TO EXISTING GRADEPROPOSED GRADE
EXISTING GRADE
TIE IN TO EXISTING GRADE
PLAN VIEW OF SIDE CHANNEL
501 Porway Avenue, Suite 101Hood River, OR 97031
541.386.9003www.interfluve.com
NASON RIGHT BANK LARGE WOODAND SIDE-CHANNEL ENHANCEMENT
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SCALE IN FEET
0 12060
SCALE: 1" = 60'
SCAL
E: 1
" = 1
2'
5x VERTICAL EXAGGERATION
LEGEND
NOT TO SCALE71 TYPICAL CROSS SECTION
PROPOSED CHANNEL
FLOODPLAIN ROUGHNESSWOOD, TYP, SEE SHEET 9
HABITAT COVER WOOD,TYP, SEE SHEET 9
EXISTING CONTOURS (1-FT INTERVAL)
PROPOSED CONTOURS (1-FT INTERVAL)
LIMITS OF DISTURBANCE
EXISTING CHANNEL
PROPOSED CHANNEL
PROPOSED CENTERLINE ALIGNMENT
TEMPORARY ACCESS ROAD
4+00
HABITAT COVER WOOD,TYP, SEE SHEET 9
HABITAT COVERWOOD, SEE SHEET 9
HABITAT COVERWOOD, SEE SHEET 9
LOCK LOG INTO EXISTINGTREES AND/OR PILE
FASTEN LOGS TO PILE
PROPOSED GRADE
EXISTING GRADE
OHW
OLW
NOTES:
SPECIFIC ORIENTATION OF LOGS AND BALLAST MATERIALSMAY VARY FROM TYPICAL DRAWINGS DEPENDING ON SIZEAND SHAPE OF MATERIAL DELIVERED OR SALVAGED.
BRACING TO EXISTING TREES OR INSTALLED VERTICALLOGS WILL OCCUR AT LOCATIONS IDENTIFIED IN THE FIELDTO PROVIDE HORIZONTAL STABILITY. FILLER LOGS ANDTREE TOPS WILL BE INSTALLED AT "RACKING" LOCATIONSTO EMULATE NATURAL DEBRIS ACCUMULATIONS AND TOOPTIMIZE FISH HABITAT.
T
O
P
O
F
B
A
N
K
T
O
P
O
F
B
A
N
K
NOT TO SCALE81 SECTION - TYPICAL BACKWATER HABITAT WOOD
FLOW
COVER HABITAT LOGS
T
O
E
O
F
B
A
N
K
T
O
E
O
F
B
A
N
K
SLASH
PARTIALLY BURIED LOGS
VERTICALSNAG
NOT TO SCALE82 PLAN - TYPICAL BACKWATER HABITAT WOOD
501 Porway Avenue, Suite 101Hood River, OR 97031
541.386.9003www.interfluve.com
LWM TYPICAL DETAILS
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EXISTING GRADE
FASTEN LOGS TO PILE
LOGFASTEN LOGS TO PILE
VERTICAL SNAG
PROPOSED GRADE
FASTEN LOGS TO PILE
LOGVERTICAL SNAG
POOL
FLOW
OHW
OLW
NOT TO SCALE94 PLAN - TYPICAL HABITAT COVER WOOD
NOT TO SCALE93 SECTION - TYPICAL HABITAT COVER WOOD
VIBRASONICALLYDRIVEN TIMBERPILE, TYP
NOTES
SPECIFIC ORIENTATION OF LOGS AND BALLAST MATERIALS MAY VARY FROM TYPICALDRAWINGS DEPENDING ON SIZE AND SHAPE OF MATERIAL DELIVERED OR SALVAGED.
BRACING TO EXISTING TREES OR INSTALLED VERTICAL LOGS WILL OCCUR ATLOCATIONS IDENTIFIED INTHE FIELD TO PROVIDE HORIZONTAL STABILITY.
ACCEPTABLE VIBRASONIC PILE DRIVING EQUIPMENT SHALL INCLUDE: HMC MOVAXSONIC SIDE GRIP VIBRATORY PILE DRIVER – MODEL SP80 OR EQUIVALENT.INSTALLATION BY EXCAVATION, HAMMERING OR VIBRATORY PLATE COMPACTORSHALL NOT BE ALLOWED.
15'
MIN
LOG WITHROOTWAD
SLASHLOG WITHOUTROOTWAD
VIBRASONICALLYDRIVEN TIMBERPILE, TYP
LOG WITH ROOTWAD
LOG WITHOUTROOTWAD
NOT TO SCALE91 PLAN - TYPICAL FLOODPLAIN ROUGHNESS WOOD
NOT TO SCALE92 SECTION - TYPICAL FLOODPLAIN ROUGHNESS WOOD
FLOW
FLOW
501 Porway Avenue, Suite 101Hood River, OR 97031
541.386.9003www.interfluve.com
LWM TYPICAL DETAILS
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