Hydrologic data collected during the 1994 Lake Mills drawdown experiment, Elwha River, Washington

128 Pages·2000·6.1 MB·English

by  Childers, D. and Kresch, D. et al.

Hydrologic Data Collected During the
Drawdown
1994 Lake Mills Experiment,
Elwha Washington u^b
River,
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Prepared in cooperation with
BUREAU OF RECLAMATION, p
U.S. GEOLOGICAL iSURVEY ^^«-^^, NATIONAL PARK SERVICE,
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Water-Resources Investigations Reportd^-4215 and LOWER ELWHA
KLALLAM TRIBE
USGS
scienceforachangingworld
Cover: Photo of Glines Canyon Dam, Lake Mills, and Olympic National Park mountain
peaks. Photo provided by National Park Service, Washington.
Hydrologic Data Collected During the 1994
Lake Mills Drawdown Experiment,
Elwha Washington
River,
By DALLAS CHILDERS, DAVID L. KRESCH, STEVEN A. GUSTAFSON,
TIMOTHY RANDLE*, JAMES T MELENA*, AND BRIAN CLUER*
J.
* Bureau of Reclamation, Denver, Colorado
* U.S. National Park Service, Fort Collins, Colorado
GEOLOGICAL SURVEY
U.S.
Water-Resources Investigations Report 99-4215
Prepared in cooperation with the
BUREAU OF RECLAMATION,
NATIONAL PARK SERVICE, and
LOWER ELWHA KLALLAM TRIBE
Tacoma, Washington
2000
U.S. DEPARTMENT OF THE INTERIOR
BRUCE BABBITT, Secretary
GEOLOGICAL SURVEY
U.S.
Charles G. Groat, Director
The use offirm, trade, and brand names in this report is foridentification purposes
only and does not constitute endorsement by the U.S. Geological Survey.
For additional information write to: Copies of this report can be purchased
from:
District Chief U.S. Geological Survey
U.S. Geological Survey Information Services
1201 Pacific Avenue, Suite 600 Box 25286
Tacoma, Washington 98402 Federal Center
Denver, CO 80225
CONTENTS
Abstract 1
Introduction 2
Purpose and scope 4
Previous investigations 4
Acknowledgments 4
Description ofthe area 5
Geology 5
Climate and hydrology 5
Description ofthe drawdown experiment 9
Hydrologic datacollected during the drawdown experiment 9
Streamflow and sedimentdischarge 9
Waterquality 14
Quality assurance 19
Sediment deposits 19
ElwhaRiverstreambed 19
ElwhaRivergravel bars 19
Lake Mills delta 22
Lake Mills bed 22
Cross-section surveys 22
Coordinate system 22
Vertical datum 25
Cross-section locations 25
Cross-section survey methods 25
Land surveys 25
Bathymetric surveys 28
Cross-section data 28
Observedchannel changes 32
Photographs 33
Aerial photographs 33
Oblique time-lapse photographs 33
Summary 37
References cited 38
Glossary 39
FIGURES
1. Photograph ofElwha Dam, powerhouse, spillway channel, andLakeAldwell 3
2. Photograph ofGlines Canyon Dam 3
3a. Map showing study area in the lowerElwhaRiverValley and locations ofstreamflow and sediment
data-collection sites ELBR, ELWP, ELDM, and ELWS 6
3b. Aerial photograph showing locations ofstreamflow and sedimentdata-collection sites
ELWW,ELDl,andELD2
7
4. Graph showingdaily streamflowrecord atsite 12045500, ElwhaRiveratMcDonald Bridge (ELWP),
forthe 1994 wateryear 8
:
5a-e. Graphs showing continuous record ofstreamflow and suspended-sedimentconcentration,
instantaneous measurements ofstreamflow, and suspended-sediment samples:
a-c. at sites on the Elwha River, Washington 12
d. at site 12045500, Elwha Riverat McDonald Bridge (ELWP), and continuous record of
suspended-sediment concentration andsuspended-sediment samples atsite 12045200,
Elwha River at Altaire Bridge (ELBR) 13
e. at site 12046100, Elwha Riverbelow ElwhaDam (ELDM), and continuous recordof
suspended-sediment concentration and suspended-sediment samples atsite 12046300,
Elwha Riverdiversion below Elwha Dam (ELWS) 13
6. Photograph ofsampler used to collect Elwha River bedload samples 15
7. Photograph ofbedload sampling atsite 12044900, ElwhaRiveraboveLakeMills (ELWW),
from a boat using atetherline attachedto the boat gunnel 15
8a-c. Graphs ofsuspended-sediment and bedloaddischarges forsamples collected:
a. atsite 12044900, Elwha Riverabove Lake Mills (ELWW) 16
b. at site 12044910, Elwha RiverDelta site 1 atLakeMills (ELDl) 16
c. at site 12044920, Elwha RiverDelta site 2 atLakeMills (ELD2) 16
8d-f. Graphs showing percentageoftotal sedimentdischarge that is contributedby bedload for samples collected:
d. at site 12044900, Elwha Riverabove Lake Mills (ELWW) 16
e. at site 12044910, Elwha RiverDelta site 1 atLakeMills (ELDl) 16
f. at site 12044920, ElwhaRiverDeltasite 2 atLakeMills (ELD2) 16
9-10. Photographs ofsuspended-sediment sampling using:
9. along wading rod and a DH-48 suspended-sediment samplerfrom aboatatsite 12044910,
ElwhaRiver Deltasite 1 atLake Mills (ELDl) 17
10. a standard wading rod and aDH-48 suspended-sedimentsamplerfrom aboatat site 12044920,
Elwha River Deltasite 2 atLake Mills (ELD2) 17
11-13. Photographs showing
11. wading-rod-mounted DH-81 water-quality and suspended-sedimentsampler 18
12. three-inch pipe dredge used tocollect bed-material samples 20
13a. gravel bar surface nearsite 12044910, Elwha RiverDelta site 1 atLake Mills (ELDl) 20
13b. cut bank showing surface armoring and finer-grained subsurface sediment nearsite
12044910, Elwha River Delta site 1 atLake Mills (ELDl) 21
14. Map showing Lake Mills sedimentation areas and locations oflakebed samples ELBED and
EBED01-EBED08 23
15-19. Photographs showing:
15. topset beds overlyingforeset beds nearsite 12044920, ElwhaRiverDeltasite2 at
Lake Mills (ELD2) 24
16. new deltaforming immediately downstream oftoe oftheexposed olderdelta 24
17. locations ofcross sections 3 through 17 surveyed on theLake Mills Delta 26
18. land survey, with atotal station and prism, ofaLake Mills Deltacross section 27
19. bathymetric survey crew from the Lower Elwha KlallamTribe and boatused to survey,
with an electronic distance meterand fathometer, LakeMills Deltacrosssections that
were toodeep to wade 27
20a-l. Graphs showing surface elevation ofLake Mills Delta:
a-d. cross-sections 6-9 29
e-h. cross-sections 10-13 30
i-i. cross-sections 14-17 31
21 Photograph showing upstream reach ofthe rightchannel nearsite 12044910, Elwha RiverDelta
.
site 1 at Lake Mills (ELDl), looking upstream toward the head ofthe riffle 32
22-24. Photographs showing time-lapse photographic sequence from cameralooking at:
22. downstream reach ofthedeltaon April 10, 14, 20, 24, and 28, 1994 34
23. middle reach ofthe delta on April 10, 14, 20, 24, and 28, 1994 35
24. upstream reach ofthe deltaon April 10, 14, 20, 24, and 28, 1994 36
IV
TABLES
la. Lake Mills drawdown experimentstreamflow and sedimentdata-collection sites 10
lb. Types ofdatacollected at streamflow and sedimentdata-collection sites during the Lake Mills
drawdown experiment 10
2a. Streamflow measurements made atsite 12044900, ElwhaRiver aboveLake Mills (ELWW) 41
2b. Streamflow measurements made atsite 12044910, Elwha River Deltasite 1 atLake Mills (ELDl) 41
2c. Streamflow measurements made at site 12044920, Elwha River Deltasite 2 atLake Mills (ELD2) 41
2d. Streamflow measurements made at site 12045500, Elwha River atMcDonald Bridge (ELWP) 42
2e. Streamflow measurements made atsite 12046100, ElwhaRiverbelow ElwhaDam (ELDM) 42
3. Daily-mean discharge atdata-collection sites during the Lake Mills drawdown experiment 43
4a. Suspended-sedimentdata from samples collected at site 12044900, Elwha Riverabove
Lake Mills (ELWW) 44
4b. Suspended-sedimentdata from samples collected atsite 12044910, Elwha RiverDeltasite 1
atLake Mills (ELDl) 45
4c. Suspended-sedimentdata from samples collected atsite 12044920, Elwha RiverDeltasite 2
at Lake Mills (ELD2) 46
4d. Suspended-sedimentdata from samples collected atsite 12045200, ElwhaRiverat
Altaire Bridge (ELBR) 47
4e. Suspended-sedimentdata from samplescollected atsite 12045500, Elwha Riverat
McDonald Bridge (ELWP) 48
4f. Suspended-sedimentdatafrom samplescollected at site 12046100, ElwhaRiverbelow
Elwha Dam (ELDM) 49
4g. Suspended-sediment datafrom samples collected at site 12046300, Elwha Riverdiversion below
Elwha Dam (ELWS) 50
5a. Suspended-sedimentparticle-size distribution from samples collected at site 12044900, Elwha River
above Lake Mills (ELWW) 51
5b. Suspended-sediment particle-size distribution from samples collected at site 12044910, ElwhaRiver
Delta site 1 at Lake Mills (ELDl) 51
5c. Suspended-sediment particle-size distribution from samples collected at site 12044920, Elwha River
Deltasite 2 at Lake Mills (ELD2) 52
5d. Suspended-sediment particle-sizedistribution from samples collected at site 12045500, ElwhaRiver
at McDonald Bridge (ELWP) 52
5e. Suspended-sediment particle-sizedistribution from samples collected at site 12046100, Elwha River
below Elwha Dam (ELDM) 52
6a. Bedload discharge andparticle-size distribution from samples collected at site 12044900, Elwha River
above Lake Mills (ELWW) 53
6b. Bedload discharge and particle-sizedistribution from samples collected at site 12044910, ElwhaRiver
Delta site 1 at Lake Mills (ELDl) 57
6c. Bedload discharge and particle-sizedistribution from samples collected at site 12044920, Elwha River
Deltasite 2 at Lake Mills (ELD2) 61
7a. Water-quality constituentconcentrations measured in streamflow samplescollected atsite 12044900,
ElwhaRiverabove LakeMills (ELWW) 63
7b. Water-quality constituentconcentrations measured in streamflow samplescollected atsite 12044920,
Elwha River Delta site 2 atLake Mills (ELD2) 66
7c. Water-quality constituentconcentrations measured in streamflow samples collected atsite 12045500,
Elwha River atMcDonald Bridge (ELWP) 69
7d. Water-quality constituent concentrations measured in streamflow samples collected at site 12046100,
Elwha River below ElwhaDam (ELDM) 72
7e. Concentrations ofconstituents in bed-sedimentsamples collected at site 12045000, Lake Mills bed
nearGlines Canyon Dam (ELBED) 75
8. Particle-sizedistribution ofwetted channel bed sedimentfrom samples collected at site 12044900,
ElwhaRiveraboveLakeMills (ELWW) 77
1
9a. Particle-sizedistribution ofgravel bardeposits from surface particle counts and subsurface bulk
samples ofsedimentcollected at site 12044900, ElwhaRiveraboveLake Mills (ELWW) 78
9b. Particle-sizedistribution ofgravel bardeposits from surface particle counts and subsurface bulk
samples ofsedimentcollected at site 12044910, ElwhaRiverDeltasite 1 atLake Mills (ELD1) 79
10. Particle-sizedistribution and bulkdensity ofthe delta sedimentdeposit from surface bulk samples
collected at site 12044920, Elwha RiverDelta site 2 at Lake Mills (ELD2) 80
11. Summaries ofestimated volumes and particle-size distributions ofsedimentdeposits in LakeMills 81
12. Atterberg limits, plasticity indexes, and particle-size distribution ofsurficial samples of
lakebed sedimentcollected from the bed ofLake Mills in the fall of 1994 82
13. Coordinates and elevations ofmonuments marking the end point locations ofcross sections
surveyedduring the Lake Mills drawdown experiment 83
M
14a. Cross-section profilecoordinates forLake ills Deltadeposit, April 8, 1994 84
M
14b. Cross-section profile coordinates forLake ills Deltadeposit, April 10, 1994 87
M
14c. Cross-section profile coordinates forLake ills Deltadeposit, April 11, 1994 88
M
14d. Cross-section profile coordinates forLake ills Deltadeposit, April 12, 1994 90
M
14e. Cross-section profile coordinates forLake ills Deltadeposit, April 13, 1994 92
M
14f. Cross-section profile coordinates forLake ills Deltadeposit, April 14, 1994 94
14g. Cross-section profile coordinates forLake Miills Deltadeposit, April 15, 1994 96
14h. Cross-section profile coordinates forLakeMiills Deltadeposit, April 16, 1994 98
14i. Cross-section profile coordinates forLakeMiills Deltadeposit, April 17, 1994 100
14j. Cross-section profile coordinates forLakeMiills Deltadeposit, April 18, 1994 102
M
14k. Cross-section profile coordinates forLake ills Deltadeposit, April 19, 1994 104
141. Cross-section profile coordinates forLakeMiills Deltadeposit, April 20, 1994 106
M
14m. Cross-section profile coordinates forLake ills Deltadeposit, April 21, 1994 108
M
14n. Cross-section profile coordinates forLake ills Deltadeposit, April 22, 1994 110
M
14o. Cross-section profile coordinates forLake ills Deltadeposit, April 23, 1994 11
14p. Cross-section profile coordinates forLakeMiills Deltadeposit, April 26, 1994 114
VERTICAL DATUM
SeaLevel: In this report, "sealevel"refers tothe National Geodetic Vertical Datum of 1929—ageodetic datum derivedfrom
ageneral adjustmentofthe first-orderlevel nets ofthe United States and Canada, formerly called SeaLevel Datum of 1929.
VI
Hydrologic Data Collected During the 1994 Lake Mills
Drawdown Experiment, Elwha River, Washington
By Dallas Childers, David L. Kresch, Steven A. Gustafson, Timothy J. Randle,
James T. Melena, and Brian Cluer
ABSTRACT drawdown ofthe lake, delta erosion became
primarily lateral, as the streambed entering the
Removal ofthe Glines Canyon and Elwha
lake attained a base level limited by the lake's low-
Dams on the Elwha River in northwestern
ered level. Most ofthe eroded delta sediments
Washington has been proposed to achieve restora-
were redeposited in anew lobe extending the delta
tion ofthe ecosystem and native anadromous
about 300 feet farther into the lake at a lower ele-
fisheries ofthe river. Glines Canyon Dam, located
vation. The volume ofdelta sediment transported
13.4 miles upstream from the mouth ofthe Elwha
during the drawdown experimentwas estimatedto
River, forms Lake Mills, and Elwha Dam, located
be about 300,000 cubic yards.
4.9 miles upstream from the mouth, forms Lake
Aldwell. The most serious concern associated Two data-collection sites, one near the
with removal of the dams is the management of middle of the Lake Mills Delta and the other near
sediment that has accumulated in deltas at the its downstream end, were established to measure
the effects ofdelta erosion on the transport of
upstream ends ofthe lakes formed by the dams.
The Lake Mills Delta contains an estimated sediment and other water-quality constituents into
Lake Mills. The highest concentrations ofcon-
3.8 million cubic yards ofsediment, and the Lake
1
Aldwell Delta contains an estimated 3.9 million stituents measured were at the downstream site
cubic yards of sediment. becausethat is where mostbankerosion occurred.
The maximum concentration of suspended sedi-
The U.S. National Park Service, the Bureau
ment measured at the downstream delta site was
ofReclamation, the U.S. Geological Survey, and
the Lower Elwha Klallam Tribejointly conducted 6,1 10 milligrams per liter (mg/L). However, most
ofthe suspended sediment measured at that site
a drawdown experiment in April 1994 to deter-
must have been trapped in Lake Mills because
mine theerodibility and size gradation ofthe Lake
suspended-sediment concentrations downstream
Mills Delta sediments, the impact oflake draw- from Glines Canyon Dam did notexceed 20 mg/L.
down on sediment transport, and the impact of
sedimenterosionon waterquality. LakeMills was The average concentrations ofunfiltered
gradually lowered 18 feet over a one-week period iron and manganese measured at the downstream
to expose the delta deposits, held at a constant deltasite(23,000|J.g/Land350|ig/L, respectively)
elevation forone week, and then allowedto return were considerably greater than their ambient
to its normal operating level. concentrations measured at a site upstream from
LakeMills (200|ag/Land<10|a,g/L, respectively).
The Lake Mills Deltaeroded both vertically
However, their maximum concentrations mea-
and laterally during the drawdown experiment.
suredatsitesdownstreamfromGlinesCanyon and
Eroded banks were nearly vertical, with no signs
Elwha Dams were only 960 |ig/L and 80 |Xg/L,
ofseepage-based erosion. After the full 18-foot
respectively.
.
INTRODUCTION Although many bureaus within the Department of
Interior have contributed to the preparation ofenviron-
The Elwha River, on the Olympic Peninsula of
mental impact statements and conducted scientific
northwesternWashington, drains thenorth slope ofthe
studies, the Bureau ofReclamation is responsible for
Olympic Mountains and flows into the Staight ofJuan overseeingtheremovalofthedamsandthesatisfactory
de Fuca. In the early 1900's, two hydroelectric dams disposal ofthe sediment accumulatedbehindthedams.
were constructed on the rivertoprovideelectric power The most serious concern associated with
for development on the Olympic Peninsula. Elwha removal ofthe dams is how to manage the sediment
Dam (photo, fig. 1), located 4.9 river miles upstream accumulated in each lake. Accumulated sediment in
from the mouth ofthe Elwha River and constructed both lakes hasformeddeltasconsistingmainly ofsand-
from 1910 to 1913, formed Lake Aldwell, capacity sized and gravel-sized rocks, with smallerpercentages
about 8,100 acre-feet (Federal Energy Regulatory ofcobblesandboulders. Sandandfinersizedsediment
Commission, 1993). Glines Canyon Dam (photo, has accumulated on the lakebeds. The Lake Mills
fig. 2), located 13.4 miles upstream from the mouth of Deltacontainsanestimated 13.8 millioncubic yardsof
the river and constructed from 1925 to 1927, formed sediment, and the Lake Aldwell Delta contains an
Lake Mills, capacity about 40,000 acre-feet (Federal
estimated 3.9 million cubic yards ofsediment.
Energy Regulatory Commission, 1993). Although the Anotherconcern is protection ofthe quality of
dams helped the early development on the peninsula, municipal and industrial water supplies during and
neitherdam had fish passage facilities, and the following proposed dam removal. A Ranney collector
presence ofthe dams has caused severe problems for well situated on the right bank terrace ofthe Elwha
anadromous fish, theecosystem, and the LowerElwha River downstream from Lake Aldwell provides an
KlallamTribe. AlthoughthedamsareownedbyJames
average of28.5 ft /s (cubic feet per second) or
RiverII, Inc., they areoperatedby theDaishawaAmer- 18.4milliongallonsperdayofwatertotheCity ofPort
icaPortAngeles PaperMill to supply about40percent Angeles for municipal use (Ralph Elsworth, Superin-
ofthe power needed to run the mill (average annual tendent ofthe Port Angeles Water Department, oral
generation of 19 megawatts). Both reservoirs are commun., August 1995). Anearby diversion damalso
normally kept full and operated as run-of-the-river divertsupto 150ft /sforusebytwoPortAngelesmills
facilities. and aWashington State fish-rearing channel.
The Elwha RiverEcosystem and Fisheries The primary goal ofthe Lake Mills drawdown
Restoration Act was enacted by Congress and became experiment was to provide data to accomplish the
PublicLaw 102-495 onOctober24, 1992. Theactcalls
following:
for "full restoration ofthe Elwha River ecosystem and 1 Define boundary conditions and calibration for
native and anadromous fisheries." In 1994, the Depart- sediment transport models to predict erosion of
ment ofthe Interior, which is responsible for restora- sediment from the Lake Mills Delta deposit by
tionoftheecosystem,preparedacomprehensivereport
natural streamflow;
to Congress, "The Elwha Report, Restoration ofthe 2. Measure the effects ofLake Mills Delta erosion
Elwha RiverEcosystem and Native Anadromous Fish- ondownstream sediment load in the ElwhaRiver
eries." The report stated that the Secretary ofthe below Glines Canyon and Elwha Dams;
Interior had determined that Congress' goals could be 3. Determinethesizesofthelargeststreambedrocks
achieved only by removing Elwha and Glines Canyon that may be exposed during erosion ofdelta
Dams. Thisandfourotheralternativerestorationplans
deposits;
considered and their impacts are discussed in detail in 4. Demonstrate the manner in which the erosion
the Final Environmental Impact Statement (U.S.
occurs;
Department ofthe Interior, 1995) titled "Elwha River 5. Define waterquality before and during the exper-
EcosystemRestoration," preparedbytheNationalPark iment to answerthe following questions:
Service and others. Implementation ofthe selected a. Whatis theambient waterquality oftheElwha
alternative ofremoval ofboth dams is discussed in Riverupstream from the two reservoirs?
detail in the Draft Environmental Impact Statement b. What is the ambient waterquality (as itrelates
(U.S. Department ofthe Interior, 1996) titled "Elwha todrinking waterstandards)downstreamfrom
River Ecosystem Restoration Implementation,"
Lake Aldwell?
prepared by the National Park Service and others.