sodom and shearer dam removal effectiveness...

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Shearer Dam (

Sodom and Shearer Dam

Removal Effectiveness

Monitoring

Final Report: OWEB Grant #209-

919-8740

February 1, 2013

Prepared by:

Desiree Tullos, Ph.D., PE

Matt Cox

Cara Walter

Biological and Ecological Engineering

Oregon State University

116 Gilmore Hall

Corvallis, OR 97331

Sodom Dam Site: post-removal

Sodom Dam Site: pre-removal

Shearer Dam Site: post-removal

Shearer Dam Site: pre-removal

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Table of Contents List of Figures ................................................................................................................................. 4

1. Introduction and Project Objectives......................................................................................... 6

1.1.Background and project objectives ....................................................................................... 6

2. General site descriptions .......................................................................................................... 6

3. Methods.................................................................................................................................... 7

3.1 Dispersed Sites .................................................................................................................... 12

3.1.1 Fish ............................................................................................................................... 12

3.1.2 Habitat .......................................................................................................................... 12

3.2 Temperature ........................................................................................................................ 14

3.3 Intensive Sites ..................................................................................................................... 14

3.3.1 Sodom Dam .................................................................................................................. 14

3.3.2 Shearer Dam ................................................................................................................. 15

3.4 Streamflow gauging ............................................................................................................ 15

4. Summary of Results ............................................................................................................... 16

4.1 Dispersed sites ..................................................................................................................... 16

4.1.1 Temperature .................................................................................................................. 16

Temperature monitoring was used, in part, to investigate effects of potential ecological

impacts of changes in the flow split. Lower flow in a reach may lead to warming due to

lower volume of water. .......................................................................................................... 16

Longitudinal temperature trends in Sodom Channel: Pre- and post-removal. ...................... 16

4.1.2 Fish ............................................................................................................................... 20

4.1.3 Fish Cover..................................................................................................................... 22

4.1.4 Canopy cover ................................................................................................................ 23

4.1.5 Sreambank conditions................................................................................................... 25

4.1.6 Longitudinal profiles ................................................................................................. 26

4.1.7 Vegetation .................................................................................................................. 30

Historical Calapooia .............................................................................................................. 31

4.1.8 In-channel wood ........................................................................................................ 34

4.2 Intensive sites ...................................................................................................................... 36

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4.2.1 Sodom Dam .................................................................................................................. 36

4.2.2 Shearer Dam ................................................................................................................. 38

4.3 Discharge and flow splits .................................................................................................... 39

5. Summary and future work ..................................................................................................... 41

6. Literature Cited ...................................................................................................................... 42

Appendix A: Discharge gaging ...................................................... Error! Bookmark not defined.

Appendix B: Intensive site cross sections ...................................... Error! Bookmark not defined.

Sodom Dam site ......................................................................... Error! Bookmark not defined.

Shearer Dam site ........................................................................ Error! Bookmark not defined.

Appendix C: Photo points .............................................................. Error! Bookmark not defined.

Appendix D: Visual Inspection Checklist..................................................................................... 82

Appendix E: Temperature monitoring locations on the Sodom Channel and Calapooia River. 84

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List of Figures

Figure 1: Site map, including extents of intensive monitoring sites and locations of dispersed

sites. S1 and S2 sites are located in the Sodom channel and C1-C5 sites are all located on this

historical Calapooia River. C0 and C6 is located on the mainstem Calapooia River. .................... 8

Figure 2: The Sodom 1 dispersed site (map on left, photo on right). Site is located to the north of

Linn West Drive, 2.5 km north of the bifurcation. ......................................................................... 9

Figure 3: The Sodom 2 dispersed site (map on left, photo on right). Site is located directly to the

north of Boston Mill Rd, 6.4 km north of the bifurcation.............................................................. 9

Figure 4: The Calapooia 1 dispersed site (map on left, photo on right). Site is located east of I-5,

2.8 km downstream of the bifurcation. ......................................................................................... 10

Figure 5: The Calapooia 2 dispersed site (map on left, photo on right). Site is located alongside

Roberts Rd, 6.35 km downstream of the bifurcation. ................................................................... 10

Figure 6: The Calapooia 3 dispersed site (map on left, photo on right). Site is downstream of the

former location of Shearer Dam, 9.25 km downstream of the bifurcation. .................................. 11

Figure 7: The Calapooia 4 dispersed site (map on left, photo on right). The site is located just

upstream of the confluence between the Calapooia and the millrace at Thompson’s Mill State

Historical Park, 12.2 km downstream of the bifurcation. The two red locations are approximate

(GPS waypoints not taken due to lack of signal under dense vegetation). ................................... 11

Figure 8: The Calapooia 5 dispersed site (map on left, photo on right). Site is located

downstream of Thompson’s Mill, 13.25 km downstream of the bifurcation. .............................. 12

Figure 9: Pre-removal daily maximum temperatures collected in two Sodom Channel locations,

0.55km and 2.5km below the bifurcation in 2011. Sodom 1 corresponds to S1 in Figure 1. ....... 17

Figure 10: Post removal daily maximum temperatures collected in 3 Sodom Channel dispersed

site locations located at 0.55km, 2.5km and 6.4km below the bifurcation in 2012. ..................... 18

Figure 11: Pre removal daily maximum temperatures observed at 5 dispersed sites in the

Calapooia River in 2011. Calapooia 1- Calapooia 5 correspond to C1-C5 in Figure 1. ............ 19

Figure 12: Post removal daily maximum temperatures observed at 2 dispersed sites and 1 winter

temperature monitoring site in the Calapooia River after the removal of Sodom and Shearer

Dams in 2012. These sites are located 4.1km, 6.35km and 12.2km downstream of the

bifurcation. .................................................................................................................................... 20

Figure 13: The percent of native fish during the sampling period in 2010 and 2012 ................... 21

Figure 14: Breakdown of fish species, by location. ...................................................................... 21

Figure 15: Fish cover changes in the Sodom Channel, 2010 to 2012.......................................... 22

Figure 16: Fish cover changes in the Calapooia River, 2010 to 2012 ......................................... 23

Figure 17: Canopy cover measured at five units per site, on two dispersed sites along the Sodom

Channel. ........................................................................................................................................ 23

Figure 18: Canopy cover measured at five units per site, on five dispersed sites along the

historical Calapooia River. ............................................................................................................ 24

Figure 19: Channel longitudinal profiles at dispersed sites (S1 and S2) on the Sodom Channel.27

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Figure 20: Channel longitudinal profiles measured in 2010 and 2012 at dispersed sites (C1-C5)

on the Calapooia River.................................................................................................................. 29

Figure 22: Riparian vegetation observed at the Sodom 1 dispersed site in 2010 and 2012. ....... 30

Figure 23: Riparian vegetation observed at the Sodom 2 dispersed site in 2010 and 2012. ........ 31

Figure 24: Riparian vegetation observed at the Calapooia 1 dispersed site in 2010 and 2012. .... 32




Figure 28: Riparian vegetation observed at the Calapooia 5 dispersed site in 2010 and 2012. ... 34

Figure 29: Volume of wood measured in Sodom Channel dispersed sites.................................. 34

Figure 30: Volume of wood measured in Calapooia River dispersed sites. Note that the y axes

vary in size, so that columns representing wood volume are not obscured due to scaling effects.

....................................................................................................................................................... 35

Figure 31: Longitudinal profile for Sodom ................................................................................... 37

Figure 32: Net change in area at cross sections in the area around Sodom Dam ......................... 37

Figure 33: Longitudinal profile for the Calapooia River at Shearer Dam .................................... 38

Figure 34: Net change in cross sectional area from as-built to 2012 for cross sections in the

former Shearer Dam reservoir and downstream ........................................................................... 38

Figure 35: Calculated and measured discharge on the Calapooia River at Brownsville, the

Calapooia River at Linn West Drive, and Sodom Channel at Linn West Drive .......................... 40

Figure 36: Calculated discharge on the Calapooia River at Brownsville and Sodom Channel at

Linn West Drive with the ratio of discharges for Sodom Channel at Linn West Drive and the

Calapooia River at Linn West Drive relative to the Calapooia River at Brownsville .................. 41

Figure 37: Discharge on the Calapooia River at Brownsville Bridge ......... Error! Bookmark not

defined.

Figure 38: Rating Curve for the Calapooia River at Brownsville Error! Bookmark not defined.

Figure 39: Discharge on Sodom Channel at Linn West Drive ...... Error! Bookmark not defined.

Figure 40: Rating Curve for Sodom Channel at Linn West DriveError! Bookmark not defined.

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1. Introduction and Project Objectives

1.1.Background and project objectives

This report presents the results of geomorphic and biological monitoring around the removal of

Sodom and Shearer dams on the Calapooia River and Sodom Channel. The overarching

objectives od this effort were to 1) evaluate the effectiveness of the project in meeting objectives

to inform maintenance and modification, and 2) investigate the spatial and temporal effects of

the split flows, sediment dynamics, and channel reconfiguration associated with removing

Sodom and Shearer Dams on habitat and fish of the Calapooia River. All data are disseminated

via the project website : http://rivers.bee.oregonstate.edu/sodom-and-shearer-dam-removals-

monitoring

2. General site descriptions

The Calapooia River travels 121 km from its source in the Western Cascades before meeting the

Willamette River near Albany, Oregon. Its drainage area of 947 km2

consists of steep terrain

managed for forestry in the upper watershed transitioning to low gradient agricultural and rural

residential lands below the community of Holley (Runyon et. al 2004). The Calapooia is a winter

rain-dominated system, with majority of annual runoff occurring from November to April.

Average monthly flows at the Holley gauge (records from 1936 to 1990) ranged from 24.3 m3/s

in January to 1.2 m3/s in August.

The Sodom Channel was created in the 19th

century to divert flow for milling and to reduce

flooding impacts in the lower Calapooia basin. The Channel leaves the main channel of

Calapooia just downstream of RM 19, and carries the majority of the annual flow of the river.

Sodom Dam was originally constructed in 1890 because the Channel had diverted the entire

volume of the river. The most recent (concrete) Sodom Dam was constructed in the 1950s near

the upstream end of the Sodom Channel in order to maintain flow in the historical Calapooia

channel for use at Thompson’s Mill (OPRD 2006). The dam measured 3.4m high and 25.9m

wide (Calapooia Watershed Council, 2013). The pool behind Sodom Dam contained

approximately 4600m3 of sediment (Tetra Tech, 2008). Sodom Dam was removed in July of

2011.

Various structures have historically been in place to divert water from the historical

Calapooia channel near RM 23 into the millrace used by Thompson’s Mill. The most recent

concrete structure at Shearer Dam was built in 1956 at a location about 46 m below the millrace.

This structure measured 2.2m high and 12.2m wide. Shearer Dam was removed in August of

2011.

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Table 1: Characteristics of dispersed sites in the Sodom Channel (S1, S2) and Calapooia

River (C1-C5).

3. Methods

Study design included both intensive monitoring at the sites of dam removal and at dispersed

sites (Figure 1). Seven dispersed sites (2 in the Sodom Channel and 5 in the historical Calapooia)

were selected to represent a sample of the entire system for detailed study of bank characteristics,

habitat features and temperature (Figures 2-8). Goals and methods varied between the intensive

and dispersed sites, as described in the following sections.

Site Name

Dist DS of

bifurcation

(km)

Low Flow

Wetted

Width

(m)

Top of

Bank

Width (m)

Water

Surface

Slope

S1 2.5 11.7 28 0.31%

S2 6.4 10.5 19.9 0.18%

C1 2.8 5.3 14.3 0.12%

C2 6.35 6.8 11.7 0.31%

C3 9.25 5.9 9.1 0.47%

C4 12.2 7.8 15.2 0.02%

C5 13.25 10.6 18 0.81%

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Figure 1: Site map, including extents of intensive monitoring sites and locations of

dispersed sites. S1 and S2 sites are located in the Sodom channel and C1-C5 sites are all located

on this historical Calapooia River. C0 and C6 is located on the mainstem Calapooia River.

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Figure 2: The Sodom 1 dispersed site (map on left, photo on right). Site is located to the

north of Linn West Drive, 2.5 km north of the bifurcation.

Figure 3: The Sodom 2 dispersed site (map on left, photo on right). Site is located directly to

the north of Boston Mill Rd, 6.4 km north of the bifurcation.

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Figure 4: The Calapooia 1 dispersed site (map on left, photo on right). Site is located east of

I-5, 2.8 km downstream of the bifurcation.


alongside Roberts Rd, 6.35 km downstream of the bifurcation.

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Figure 6: The Calapooia 3 dispersed site (map on left, photo on right). Site is downstream of

the former location of Shearer Dam, 9.25 km downstream of the bifurcation.

Figure 7: The Calapooia 4 dispersed site (map on left, photo on right). The site is located just

upstream of the confluence between the Calapooia and the millrace at Thompson’s Mill State

Historical Park, 12.2 km downstream of the bifurcation. The two red locations are approximate

(GPS waypoints not taken due to lack of signal under dense vegetation).

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downstream of Thompson’s Mill, 13.25 km downstream of the bifurcation.

3.1 Dispersed Sites

3.1.1 Fish

Consistent with the surveys collected for pre-removal characterization and with USEPA’s

protocols for wadeable streams (Peck et al. 2006), fish sampling was performed by a contractor

for this study using a backpack electroshocker and hand nets. Four of the dispersed sites were

sampled annually (Figure 1): S2) Sodom Channel downstream of Boston Mill Road; C2)

Calapooia River upstream of the mill, Shearer and Spillway Dams but downstream of I5; C4)

Calapooia River upstream of the mill but downstream of Shearer and Spillway Dams; and C5)

Calapooia River downstream of the mill but upstream of the confluence with Sodom Channel.

This sampling supplements fish sampling being performed by the USEPA for a wider study

upstream of Sodom Dam on the Calapooia River, and downstream of the Sodom Channel and

Calapooia River confluence.

3.1.2 Habitat

We evaluated changes in habitat at the seven dispersed sites on the Calapooia River and

Sodom Channel. Each site consists of five contiguous transects, each of which are four active-

channel widths long, as determined at the downstream end of the each site. Sites were sampled

downstream to upstream. We modified USEPA’s EMAP procedure (Kaufmann et al. 1999), as

described below, to measure in-stream wood, canopy density, fish cover, thalweg depth, bed

sediment, water surface velocity, channel width, slope, shade angle, and bank vegetation either

along the transect or at cross sections situated at the midpoint of the transects.

Along the transects, we sampled the following features:

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Wood - All pieces in the active channel greater than 5 feet long or 0.5 feet in diameter

were tallied. The positioning (in or out of water), stability (fixed or loose), and racking

(individual or part of an accumulation) was documented for each piece of wood. In the

case of larger accumulations, we estimated the overall dimensions and porosity (e.g.

streamwise length, width, height, and volume filled with wood) as well as whether or not

the accumulation was channel spanning or the dominant side of the channel if not

channel-spanning.

Vegetation – Each bank was evaluated in two parts: downstream of the cross section and

upstream of the cross section. For each part of the bank evaluated, the species or class of

vegetation (vine, shrub, grass, mature tree) and percent of the bank covered by vegetation

class were recorded.

Bed slope and water depth - Water depth was measured with a stadia rod in the thalweg

at an interval equal to the section length divided by 12. Bed slope was determined with a

hand level and stadia rod for either half of each section or the whole section, depending

on visibility.

Substrate - Substrate was measured visually or with the bottom of the stadia rod (to

differentiate sand and silt/clay) on the left, center and right of the wetted channel at four

streamwise locations within each section: 1) the start; 2) ¼ of the length; 3) ½ of the

length (at the cross section); 4) ¾ of the length. Percent embedded was visually

estimated for substrate determined to be gravel and larger.

At cross sections, we sampled the following features:

Bank parameters - Bank slope in percent was determined by laying the stadia rod down

with the clinometer on top of it for all discrete slopes (e.g. toe, bench, to terrace) along

each bank. Bank material was identified as the dominant material and determined by

pinching for fines or visual assessment for gravels or larger. Bank height was defined as

the height above the water surface.

Channel parameters - Velocity was estimated three times by extending the stadia rod to

13 feet, laying it streamwise on the surface of the water, and timing a dogwood leaf

floating the length next to the rod. Channel width was measured from top-of-bank to top-

of-bank. Bottom width was measured as the wetted width. Shade angle was measured

from the middle of the active channel looking up to the top of the vegetation on each side

with the clinometer.

Canopy –Canopy density was measured four times at each cross section facing

downstream, upstream, river right (oriented looking downstream), and river left using a

densitometer with 17 intersections showing on the densiometer. The densiometer was

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held level approximately one foot above the water surface, and each intersection that

covered by vegetation was counted.

Fish cover –Perfect aerial coverage of ten types of potential fish cover was assessed in

each unit of each site : Macrophytes , Large and small wood, live trees/roots,

overhanging vegetation, undercut banks, boulders, artificial structures and bryophytes.

We found no artificial structures or bryophytes at any of the dispersed sites.

3.2 Temperature

Temperature was measured hourly at dispersed and intensive monitoring sites using ibutton™

sensors (model DS1921G). According to the manufacturer, these sensors are accurate to +/- 1°C

and water resistant (IP 56). Additional water resistance was gained by placing the ibutton within

two plastic layers and then within a sealed, galvanized pipe housing. The original sampling

design called for three sensors at each dispersed site, placed at various depths to examine

possible temperature stratification and locations of thermal refugia. In addition, sensors were

placed above and below the intensive monitoring sites in order to understand the magnitude of

heating enabled by the impoundment of flow behind the both dams. In the winter, a single sensor

at each site was left in place, and in some cases moved to location that is accessible year round

(e.g a nearby bridge abutment). Our experience with these particular sensors has been that they

are very unreliable (Appendix F, Tables F1 and F2) when placed in a submerged environment for

extended amounts of time. Even with a well-sealed case, water vapor caused unit failures in well

over 60% of our placements overall. Thus, we were unable to complete the temperature analysis

as originally envisioned. Longitudinal trends where simultaneous measurements do exist are

presented here.

3.3 Intensive Sites

3.3.1 Sodom Dam

Spatial extent for the intensive monitoring near Sodom Dam is approximately 300 feet upstream

of the bifurcation (River Design Group-RDG station 22+00) to 200 feet downstream on the

historical Calapooia and 2000 feet downstream on Sodom Channel (RDG station 42+00). A

combination of RTK GPS and total station field surveys were conducted annually at low water.

Surveys were conducted as a longitudinal profile and cross sections at a) each engineered riffle

crest, b) each pool that occurred between the engineered riffle structures, c) upstream of the

bifurcation to Station 22+00, d) at the bifurcation, Station 26+00, e) downstream of the

bifurcation in the historical Calapooia River (approximately 200’). Additional survey points were

collected in areas that greatly deviated from design both during the low flow survey, and soon

after changes in the channel. Surveys at the completion of dam removal and channel

construction, hereafter referred to as “as-built” surveys, were conducted by River Design Group

(RDG). Subsequent surveys were conducted by the River lab at Oregon State University (OSU).

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During summer baseflows, we completed a visual inspection checklist, developed by

OPRD (See example, Appendix E), and field surveys of the following locations: engineered

riffles, engineered log jams, vegetated soil lifts, channel reconstruction, specifically noting areas

of erosion or deposition, and the bifurcation. Surveys and inspections specifically noted areas of

sediment accumulation, discontinuous flow through coarse sediment that could lead to fish

passage barriers, and lack of flow into either of the downstream channels.

We revisited photo points during summer baseflow and for 1-2 storm events to document

the performance of the structures during higher flows. Photos were taken at multiple angles per

point. Locations established based on Federal Energy Regulatory Commission (FERC) permit

requirements for effectiveness evaluation of the structures include:

‐ 2 photo points per engineered riffle: 1 looking upstream, 1 looking downstream

‐ 1 photo point per engineered log jam

‐ 1 photo point per vegetated soil lift at each associate engineered structure

‐ 5 Representative photo points for vegetative plantings

‐ 3 photo points at the bifurcation: 1) Looking downstream, 2) Looking upstream from

Calapooia River below the bifurcation, and 3) Looking upstream from Sodom Channel

below the bifurcation

3.3.2 Shearer Dam

Intensive monitoring around Shearer Dam extended from approximately 250 feet

upstream of the Shearer Dam to 250 feet downstream. A combination of RTK GPS and total

station field surveys were conducted at low water documenting the longitudinal profile and cross

sections upstream and downstream of the Shearer Dam site. Surveys at the completion of dam

removal and channel construction, hereafter referred to as “as-built” surveys, were conducted by

RDG. Subsequent surveys were conducted by the River lab at Oregon State University (OSU).

Photo points were established prior to dam removal at points of interest and were revisited

during summer baseflow.

3.4 Streamflow gauging

For the purpose of monitoring flow allocation between the two channels, two gages were

utilized:

1. An existing OSU gauging station on the Calapooia River upstream of the bifurcation near

Brownsville. Effort for this gage was focused on continuing to develop the rating curve, and

downloading and processing flow data.

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2. A new OSU gauging station on Sodom Channel at the Linn West Drive bridge. Effort for

this telemetry-based gauging station was focused on extending the rating curve and providing

hourly water level and discharge measurements to interested parties through a website.

Discharge measurements on the Sodom Channel were subtracted from discharge on the

Calapooia River to estimate flows through the historical Calapooia channel.

On a time available basis, discharge measurements were also taken on the Calapooia River at

Linn West Drive. All discharge measurements were taken according to USGS protocols (Rantz

et al. 1982, Mueller et al. 2009) with a Price AA current meter either wading or using a crane

from a bridge, or with a Teledyne RD Instruments StreamPro. Rating curves were developed

using USGS protocols (Rantz et al. 1982, Kennedy et al. 1983, Kennedy et al. 1984). All data

were published online at the project website: http://rivers.bee.oregonstate.edu/sodom-and-

shearer-dam-removals-monitoring. Rating curves and equations are presented in Appendix A.

4. Summary of Results

4.1 Dispersed sites

4.1.1 Temperature

Temperature monitoring was used, in part, to investigate effects of potential ecological impacts

of changes in the flow split. Lower flow in a reach may lead to warming due to lower volume of

water.

Longitudinal temperature trends in Sodom Channel: Pre- and post-removal.

Longitudinal trends are represented as the difference in maximum daily temperature between two

sensors located in Sodom Channel. Due to damaged sensors, no pre-removal data is available

from S2, which is located 6.4 km downstream of the bifurcation, but was functioning in 2012 for

post-removal analysis. In addition, the upstream temperature sensor for the upstream Sodom

Intensive site also failed.

Thus, for the pre-removal condition, we compare (Figure 9) temperature from the sensors

installed a) in the Sodom Intensive site, located 0.55 km downstream of the former dam site, to

b) at the S1 dispersed site, located at Linn-West in the Sodom Channel, 2.5km downstream of

the former dam site. From these data, we see no evidence of longitudinal trend in maximum daily

temperature between the downstream Sodom Intensive monitoring site and S1 between early

June and early July of 2011.

http://rivers.bee.oregonstate.edu/sodom-and-shearer-dam-removals-monitoring

http://rivers.bee.oregonstate.edu/sodom-and-shearer-dam-removals-monitoring

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Figure 9: Pre-removal daily maximum temperatures collected in two Sodom Channel

locations, 0.55km and 2.5km below the bifurcation in 2011. Sodom 1 corresponds to S1 in

Figure 1.

Comparing post removal temperature trends (Figure 10), daily maximum temperatures

remain similar at the Sodom DS intensive and S1 sites. No evidence is seen of a longitudinal

trend between the Sodom DS intensive and S1 sites, similar to pre removal observations. The

daily maximum temperatures at the Sodom 2 site are occasionally cooler, but the relationships

between the sites become less predictable after July 1st.

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Figure 10: Post removal daily maximum temperatures collected in 3 Sodom Channel

dispersed site locations located at 0.55km, 2.5km and 6.4km below the bifurcation in 2012.

Longitudinal temperature trends in the historical Calapooia River: Pre- and post-removal

For the pre-removal condition (Figure 11), we compare daily maximum temperatures at 5

dispersed locations: 1) C1, located 2.8 km downstream of the bifurcation 2) C2, located 6.35 km

downstream of the bifurcation 3) C3, located 9.3 km downstream of the bifurcation 4) C4,

located 12.2 km downstream of the bifurcation, and 5) C5, located 13.3 km downstream of the

bifurcation. Daily maximum temperatures do not show a consistent downstream warming

pattern during this time period. In fact, maximum temperatures are generally cooler farther

downstream from the bifurcation after June 15th. This may in part be due to the dense riparian

shading in the historical Calapooia channel. It also appears that warmer water in the upstream of

portion of this channel (e.g. C1) takes about one day to travel the 10.5 km to the farthest DS site

(C5). This is most clearly apparent in the maximum on July 6th

, where temperature peaks at 23

°C for the C1 location, but peaks at 21°C on July 7th

at C5.

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Figure 11: Pre removal daily maximum temperatures observed at 5 dispersed sites in the

Calapooia River in 2011. Calapooia 1- Calapooia 5 correspond to C1-C5 in Figure 1.

For the post-removal condition (Figure 12), we examine daily maximum temperatures at

three locations in the historical Calapooia channel. Due to sensor loss, data at C1, C3 and C5 are

not available. However, data from a winter temperature monitoring location (Calapooia River at

Linn West Drive – 4.1km downstream of the bifurcation) were available and are included.

Downstream cooling is observed in daily maximum temperature values between April 1st and

early June. One pattern observed is the reduction in daily maximum temperatures in the

downstream direction. This pattern, observed post removal, is similar to the pattern observed

prior to removal in 2011.

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Figure 12: Post removal daily maximum temperatures observed at 2 dispersed sites and 1

winter temperature monitoring site in the Calapooia River after the removal of Sodom and

Shearer Dams in 2012. These sites are located 4.1km, 6.35km and 12.2km downstream of the

bifurcation.

In summary, we conclude that effects of daily maximum temperature patterns from either

changes in flow regime or changes in riparian condition are small and likely beyond our ability

to detect with this dataset.

4.1.2 Fish

Results of fish monitoring are presented as percent natives and community composition by

sampling location. Nearly 100% of the fish observed in the dispersed sites were native in both

survey periods for all sites (Figure 13). Species composition was dominated by torrent sculpin,

reticulate sculpin, redside shiner and speckled dace (Figure 14). Smallmouth bass (a non-native

species) were observed both in the historical Calapooia and the Sodom Channel. From these

limited surveys, we see no evidence of impact on species distribution or % natives associated

with the dam removals.

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Figure 13: The percent of native fish during the sampling period in 2010 and 2012

Figure 14: Breakdown of fish species, by location.

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4.1.3 Fish Cover

Fish cover in the Sodom Channel underwent little change over the study period, with the

exception of a reduction in overhanging vegetation observed at the S2 site. Filamentous algae

declined in four of five historical Calapooia sites in 2012. Small woody debris also decreased at

the same four sites. These changes likely represent the effects of increased flow in the historical

Calapooia. No clear trends were observed in the presence of large woody debris or live trees in

the channel.

Figure 15: Fish cover changes in the Sodom Channel, 2010 to 2012.

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Figure 16: Fish cover changes in the Calapooia River, 2010 to 2012

4.1.4 Canopy cover

Along the Sodom Channel (Figure 17), canopy cover increased in four of the five units at the S1

site. Slight changes within units were observed at the S2 site, but overall, canopy cover was

similar in 2010 and 2012. On the historical Calapooia channel, canopy cover (Figure 18) either

remained similar (C2 and C3) or increased slightly (C1, C4, C5). Riparian disturbances large

enough to reduce canopy cover were not observed at any of the dispersed sites.

Figure 17: Canopy cover measured at five units per site, on two dispersed sites along the

Sodom Channel.

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Figure 18: Canopy cover measured at five units per site, on five dispersed sites along the

historical Calapooia River.

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4.1.5 Sreambank conditions

Bank slopes changes were grouped into five discrete categories (Table 2). The accuracy of the

clinometers is /- 5°, so any change less than this is considered not measureable. Bank slope

values were averaged when more than one measurement existed on the same bank. Channel

width values were measured from the top of one bank to the top of the opposing bank.

Table 2: Changes in bank slope, bank height, channel width following dam removal.

Results are presented for individual cross sections in dispersed sites between 2010 and 2012.

Slope change categories are represented as follows: >+15%(++), +5% to +15%(+), +5% to -5%

(n.c. – no change), -5% to -15%(-), >-15%(--). Channel width in the table represents the

difference in top-of-bank width.

Across the period (September 27 to October 15) of the 2010 survey, the estimated stage

and discharge in the Sodom Channel were 0.4 m (1.3 ft) and 3.3 cms (115 cfs), respectively. On

the historical Calapooia, estimated stage and discharge were 0.3 m (0.9 ft) and 1.5 cms (53 cfs),

respectively. In 2012, our survey dates spanned fewer days (September 12-14) and flows were

very different. Stage and discharge were both much lower, 0.3 ft (0.1 m) and 0.3 cms (9 cfs)

respectively, in the Sodom Channel. In contrast, stage and discharge in the historical Calapooia

were both higher that pre-project conditions, 0.4 m (1.3 ft) and 3.3 cms (115 cfs), respectively.

In the Sodom Channel, channels appear to have mostly steepened, narrowed, and lowered

between 2010 and 2012. The only exceptions to this trend are the right banks of S2, where slopes

flattened by 2012. S1 and S2 sites are located 2.5 and 6.4 m, respectively downstream of the

sites. However, without analysis of the streambank stability, we are unable to confirm that the

extensive changes in bank width are associated with dam removal. For example, it is possible

that some of the estimated changes in top widths are unreliable due to difficulty in identifying the

top of bank in the heavily vegetated channels under different flow conditions. Analysis of

Unit 1 Unit 2 Unit 3 Unit 4 Unit 5

LB ++ n.c. ++ ++ ++ -1.2

RB ++ ++ - n.c. ++ -0.9

LB ++ + ++ + - -0.2

RB n.c. - -- n.c. - -0.6

LB ++ + n.c. + ++ 0.2

RB - -- n.c. ++ -- 0.2

LB ++ + - + n.c. -0.3

RB - -- n.c. -- - -0.2

LB -- ++ - ++ -- -0.3

RB - + - n.c. ++ -0.7

LB ++ n.c. ++ ++ ++ -1.4

RB ++ ++ + n.c. ++ -0.6

LB -- ++ n.c. -- ++ -0.5

RB n.c. -- + + -- 0.1

C4

Slope Changes

6.1

C5 -2.73

Average Change in

Bank Height (m)

Average Change in

Channel Width at Top of

Bank (m)

Site Name Bank

C1

-0.1C2

-2.9

C3 1.26

S1 -8

S2 -3.7

26

streambank stability across the study periods, to be completed, will provide addition insight into

the reliability of these observations and the mechanisms for changes in streambank geometry.

Along the historical Calapooia River, units both narrowed (C1, C2, and C5) and widened

(C3, C4). Change in bank height was low for most units. Patterns in bank steepening are mixed;

both C1 and C2 steepened on the left bank while the slope steepened on the right bank,

suggesting erosion on the left bank. Most of the left and right banks at C3 either steepen or

become flatten simultaneously. Most banks steepen at site C4, where the channel width increases

substantially. The change in channel width and slope at C4 corresponds with an increase in wood

volume (Figure 30). Alternating banks steepen and become less steep at site C5.

4.1.6 Longitudinal profiles

Along the Sodom Channel, the locations of pools dramatically shift between the two periods for

both S1 and S2 sites (Figure 19). Because these sites are so far downstream (Table 1), it is

unlikely that these changes are associated with the dam removal. Without additional information

on the background, natural variability of the bed profile, we also cannot conclude whether

changes are associated with the changes in winter flows (See Section 4.3, Table 3, and Figure 36

for pre- and post-project flow splits between the historical Calapooia and Sodom Channel). Thus,

based on maximum GPS error (+/- 3m) in reoccupying former survey locations, we can only

conclude that these large shifts in the locations of these pools on the Sodom Channel are not

surveying artifacts but are legitimate channel changes that occurred across the study period.

27

Figure 19: Channel longitudinal profiles at dispersed sites (S1 and S2) on the Sodom

Channel.

Patterns of incision and aggradation varied across the dispersed sites on the historical

Calapooia between the two study periods (Figure 20). One site (C1) incised, two sites aggraded

(C3, C5), and two sites (C2, C4) experienced local erosion and deposition. It is possible that

channel changes are a result of the flow split (See Section 4.3 for pre- and post-project flow

splits between the historical Calapooia and Sodom Channel), but again, without some evidence

of baseline variability at these sites, conclusions cannot be drawn.

29

Figure 20: Channel longitudinal profiles measured in 2010 and 2012 at dispersed sites on

the Calapooia River.

30

4.1.7 Vegetation

For the purposes of this report, vegetation data has been lumped into four broad categories

(woody, shrubs, grass/forbs and bare). In general, grass and forbs were most prevalent in

locations where small bank failures had recently exposed sediment to plant colonization. In

reaches with more mature vegetation, the understory was so dense that very few areas of

grass/forbs were observed. The most commonly observed wood species in our vegetation

surveys were red osier dogwood (Cornus Stolonifera) and Oregon ash (Fraxinus Latifolia). The

most commonly observed shrub species included Himalayan blackberry (Rubus Discolor),

snowberry (Symphoricarpus Albus), and red flowering currant (Ribes Sanguineum). By far the

most commonly occurring plant in the forb/grass category was reed canary grass (Phalaris

Arundinacea).

Along the Sodom Channel, the presence of forbs decreased between 2010 and 2012

(Figure 22) for most units in S1 and S2. More woody vegetation was observed on the left bank at

S1, while less was observed on the right bank, where woody vegetation was replaced primarily

by shrubs. At S2, woody vegetation comprised more of the bank vegetation in 2012 than in 2010.

Percent of the bank with no vegetation was lower in 2012 that 2010 for nearly all units in S1 and

S2, replaced by a mixture of woody and shrubby vegetation.

Figure 21: Riparian vegetation observed at the S1 dispersed site.

31

Figure 22: Riparian vegetation observed at the S2 dispersed site.

Historical Calapooia

Across most of the dispersed sites on the historical Calapooia, bare areas observed in 2010 were

not present in 2012 (Figures 23-27). Grass and forbs were also reduced, with a few exceptions

(C1, Unit 1, right bank; C5, Unit 1, right bank; C5, Unit 5, left bank). For these units where

grasses and forbs were not lower in 2012, the opposite bank became much less steep and the

bank where the grass/forbs were observed became steeper. This is consistent with initial

observations in these units that area of bank failure tended to be colonized with reed canary

grass.

For many areas in C3, C4 and C5 (Figures 25-27), it appears that woody vegetation was

replaced by shrubs in 2012. However, we do not believe this shift actually occurred. Instead, we

believe the difference may be related to a classification discrepancy; Field technicians classified

red osier dogwood as woody in 2010 and as a shrub in 2012. The banks of these sites are heavily

overgrown, with very little undergrowth.

32

Figure 23: Riparian vegetation observed at the C1 dispersed site.


33



34


4.1.8 In-channel wood

Very little wood was present at either of the dispersed sites on the Sodom Channel in 2010

and 2012 (Figure 28). At S2, one somewhat large accumulation (10 m3in Unit 4 of was

associated with one large fallen tree.

Figure 28: Volume of wood measured in Sodom Channel dispersed sites.

Much more wood was observed in the historical Calapooia (Figure 29) than in the Sodom

Channel, and the volume of wood varied more in the historical Calapooia than in the Sodom

Channel between the two study periods. Both the import of smaller pieces of wood and the

35

export of both large individual pieces of wood and accumulations account for the differences

between study periods, and indicate that wood movement was active in the historical Calapooia

channel post dam removal. For example, several sites (C1, C3 and C5) had greater accumulation

of wood in 2012 than in with 2010 (Figure 29). This increase in wood volume consisted mainly

of numerous smaller pieces of wood. Both C2 and C4 lost wood between 2010 and 2012: Site C2

had a single large single piece of wood present in 2010 that was not present in 2012, while a

large wood accumulation present in C4 in 2010 was not observed in 2012. However, wood

volumes in the other units of C2 were similar or lower in 2012 than in 2010, while wood volume

in C4 increased wood volume in the remaining four units by 2012.

Figure 29: Volume of wood measured in Calapooia River dispersed sites. Note that the

scales on the y-axes are not consistent.

36

4.2 Intensive sites

4.2.1 Sodom Dam

As can be seen from the longitudinal profile (Figure 30), change in channel area (Figure 31), and

cross sections (Appendix C), the Sodom Channel above, within, and downstream of the influence

of Sodom Dam greatly changed as a result of the channel reconstruction (pre-removal June 2011

to as-built November 2011), and from the changes in flows during the 2012 water year (as-built

to post-removal June/July 2012). A maximum of approximately 10 feet of erosion occurred

between the as-built and the June/July 2012 surveys for the pool (3300 m) above the former dam

site. In contrast, the historical Calapooia River underwent few changes at the cross section 200

feet downstream of the bifurcation (Figure 31). There was little net change for cross sections

outside of the reconstructed area, although the most upstream cross section at station 22+00’

changed in shape with a ~50’ shift toward river right of a mid-channel bar (Appendix C).

In cross-section, there were dramatic changes upstream of and within the middle riffle of

the reconstructed area, starting at cross sections at 32+00’ and continuing through 35+50’

(Appendix C). At its maximum, the river right bank retreated 60 feet and the bed lowered up to

15 feet, resulting in erosion of a total volume of approximately 5,000 cubic yards of material.

There were also moderate changes in the river left bank within the most upstream riffle between

cross sections at 28+95’ and 30+40,’ including creation of a backwater channel and natural log

jam. At the cross section at 30+40’ within the upstream riffle, the backwater channel visible in

the 2012 survey appears to be a reversion to the pre-removal bed elevation for that cross section.

In addition to the changes highlighted from the channel surveys, we identified several

changes in 2012 relative to the as-built condition from the visual inspection (Appendix E) of the

engineered riffles, log jams, and vegetated soil lifts. The primary change visually noted at the

engineered riffles was the exposure of the large blocks of rocks making up the ribs for each

riffle. The ribs were exposed for all three riffles: primarily on the banks for the middle and

downstream riffles, and across the entire channel for the most upstream riffle. For the engineered

log jams, all structures remained largely intact. We observed small amounts of upstream

sediment accumulation at the most downstream river left and most upstream river right jams.

Moderate amounts of erosion occurred upstream and adjacent to the other two river left jams and

the river right jam immediately upstream of the bank failure, between 32+00’ and 35+50’ cross

sections. Finally, five of the nine vegetated soil lift were completely intact and growing.

Approximately 1/3 to all of the structure’s length washed away from the remaining four lifts.

37

Figure 30: Longitudinal profile for Sodom Channel.

Figure 31: Change in area at cross sections in the area around Sodom Dam. Positive values

represent deposition and negative values represent erosion.

38

4.2.2 Shearer Dam

There were few changes in the bed and banks of the former Shearer Dam reservoir area and

immediately downstream between the as-builts and 2012 surveys (Figure 32, Appendix C). The

largest changes in cross sectional area were on the river left bank of cross sections at 13+76’ and

13+92’ directly adjacent to the former dam location (Figure 33).

Figure 32: Longitudinal profile for the Calapooia River at Shearer Dam

Figure 33: Net change in cross sectional area from as-built to 2012 for cross sections in the

former Shearer Dam reservoir and downstream

39

4.3 Discharge and flow splits

The project sites experienced several moderately-sized storm events over the study period

(Figure 35). Unfortunately, the range of the pressure transducer installed at Sodom Channel at

Linn West Drive was insufficient to capture the peak for several storms as indicated by the

dashed line in Figure 34. Thus, discharges above the dashed gray line was estimated based on

relationships with nearby USGS-gaged streams (Mohawk River near Springfield: 14165000,

South Santiam below Cascadia: 14185000). However, we also note that peaks above the range of

the pressure transducer were primarily those that overtopped banks upstream and downstream of

the gaging station and therefore difficult to accurately capture anyway.

Prior to project implementation, the gaging station at Sodom Channel at Linn West Drive

captured several storm events, including the annual peak. We estimate that this event has a

recurrence interval of 1.6 to 3.4 years. After the project, similarly sized and larger events

occurred. The largest event in January of 2012, with a recurrence interval estimated to be

between 1.8 and 5.6 years.

The split of flow between the historical Calapooia River and Sodom Channel was highly

unequal prior to the dam removal and did not appear to vary with discharge (Table 3, Figure 36).

Post-project ratios varied more with discharge, such that more flow was conveyed down the

historical Calapooia during moderate discharges (e.g. 12/22/11) and less flow was conveyed

down the historical as discharge increased (Table 2). Thus, more higher flow events were

conveyed down the historical Calapooia in 2012, both because 2012 was a wetter year and

because the historical Calapooia conveys relatively more of the moderate flows than pre-project.

Table 3. Percent of Brownsville flows that are conveyed down historical Calapooia River.

Note that ratios are relative; At higher flows, more tributaries are activated and thus the flows at

the Brownsville gage become less representative of flows just above the bifurcation. Results are

sorted in increasing values of flow at Brownsville.

Date Historical Calapooia at

Linn West (cfs) Brownsville (cfs)

Percent of Brownsville flow

in historical Calapooia

2/8/11 37 263 0.14

4/8/11 170 1010 0.17

4/7/11 190 1210 0.16

1/18/11 309 2367 0.13

3/16/11 284 2777 0.1

12/22/11 60 40 1.49

1/4/12 204 612 0.33

2/24/12 250 1060 0.24

2/22/12 256 1433 0.18

1/22/12 372 2960 0.13

40

Figure 34: Calculated and measured discharge on the Calapooia River at Brownsville, the

Calapooia River at Linn West Drive, and Sodom Channel at Linn West Drive.

41

Figure 35: Calculated discharge on the Calapooia River at Brownsville and Sodom

Channel at Linn West Drive. The ratio of discharges for Sodom Channel at Linn West Drive

and the Calapooia River at Linn West Drive relative to the Calapooia River at Brownsville are

presented on the secondary y-axis.

5. Summary and future work

The removal of Sodom and Shearer dams appears to have limited effects on the channel

morphology or ecological of the Calapooia River system. The most obvious effects are those on

the flow split; more of the low and moderate flows are conveyed through the historical Calapooia

River (Figure 36, Table 3). Some morphological changes were observed, including variability in

the longitudinal profiles (Figures 19 and 20) and streambank conditions (Table 2), but could not

be conclusively linked to the dam removals or changes in flow splits. No clear evidence of effect

from the projects on temperature, vegetation, fish, or various features of the channel habitat was

observed.

Further analysis, underway, is needed to a) link streambank changes to veg changes, and

b) characterize streambank stability, using the USDA’s Bank Stability and Toe Erosion Model

(BSTEM) model, to identify mechanisms for observed changes in streambank geometry.

42

6. Literature Cited

Calapooia Watershed Council. 2013. Sodom Shearer Dams Fish Passage Improvement and Flow

Management. Accessed January 17, 2013. http://www.calapooia.org/projects/sodom-dam-

fish-passage-improvement-and-flow-management/

Kaufmann, P.R, P. Levine, E.G. Robison, C. Seeliger, and D.V. Peck. 1999. Quantifying

Physical Habitat in Wadeable Streams. EPA/620/R-99/003. U.S. Environmental Protection

Agency, Washington, D.C.

Kennedy, E. J. 1983. Computation of Continuous Records of streamflow. Techniques of Water-

Resources Investigations of the United States Geological Society Chapter A13.

Kennedy, E. J. 1984. Discharge Ratings at Gaging Stations. Techniques of Water-Resources

Investigations of the United States Geological Society Chapter A10.

Mueller, David S., and Wagner, Chad R. 2009. Measuring Discharge with Acoustic Doppler

Current Profilers from a Moving Boat. U.S. Geological Survey Techniques and Methods 3A-

22.

Oregon Parks and Recreation Department (OPRD). 2006 – Thompson’s Mills State Heritage

Site, Master Plan.

Peck, D. V., A. T. Herlihy, B. H. Hill, R. M. Hughes, P. R. Kaufmann, D. J. Klemm, J. M.

Lazorchak, F. H. Mc Cormick, S. A. Peterson, P. L. Ringold, T. Magee, and M. R. Cappaert.

2006. Environmental Monitoring and Assessment Program: Surface Waters Western Pilot

Study-field operations manual for wadeable streams. EPA 620/R-06/003. US Environmental

Protection Agency, Washington, DC.

Rantz, S.E. and others, 1982. Measurement and Computation of Streamflow: Volume 1.

Measurement of Stage and Discharge. Geological Survey Water Supply Paper 2175.

Runyon J, Andrus C, Schwindt R. 2004. Calapooia River Watershed Assessment. Calapooia

Watershed Council: Brownsville, OR.

Tetra Tech 2008. Preliminary Assessment and Conceptual Site Model: Sodom Dam Conversion

Project, Calapooia River/Sodom Channel. Linn Country, OR. Prepared for Oregon Parks and

Recreation Department and the Army Corps of Engineers.

http://www.calapooia.org/projects/sodom-dam-fish-passage-improvement-and-flow-management/

http://www.calapooia.org/projects/sodom-dam-fish-passage-improvement-and-flow-management/

sodom and shearer dam removal effectiveness...

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