Auke Lake Watershed Assessment


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Auke Lake Watershed Assessment
Auke Lake Watershed in Juneau, Alaska
Prepared by the Juneau Watershed Partnership April 2009
The Juneau Watershed Partnership (JWP) is a nonprofit organization whose mission is to promote watershed integrity in the City and Borough of Juneau through education, research, and communication while encouraging sustainable use and development.

Statement of Need and Purpose Situated approximately 12 miles north of Juneau, Alaska, Auke Lake is an anadromous system supporting coho, sockeye, pink and chum salmon, as well as cutthroat trout, rainbow trout and Dolly Varden char (Bethers, 1996). The Auke Lake watershed is a popular recreational area for Juneau residents, serves as a backdrop for the University of Alaska-Southeast campus, is a growing residential area, and hosts a NOAA/NMFS research facility on its outlet. The purpose of this watershed assessment is to compile existing data into a single document, in order to identify data gaps and provide recommendations for further studies. This document also provides the City and Borough of Juneau (CBJ) and the public with an overview of the current condition of the Auke Lake watershed, and outlines management recommendations to ensure the sustainability of fish habitat and recreational and aesthetic values. The results of this assessment should be used to guide watershed management of this valuable lake system. The intention is that this report will be utilized by CBJ staff, the CBJ Planning Commission, Wetlands Review Board, the City Assembly, as well as Juneau residents and local, state and federal agencies involved in conservation and land management decisions within the Auke Lake watershed. Acknowledgements Production of this document was made possible through a grant from the US Fish and Wildlife Service’s Coastal Conservation program, and could not have been completed without the help of Neil Stichert and Shannon Seifert, U.S. Fish and Wildlife Service; Samia Savell, Natural Resources Conservation Service; Thatcher Brouwer; Jerry Taylor, National Marine Fisheries Service; and the JWP Board of Directors. Many thanks go to the members of our technical advisory committee and to all of our neighbors who came and participated in our community meetings. Special thanks to the Mayor, Assembly members and staff of the City and Borough of Juneau.
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TABLE OF CONTENTS 1. Introduction
1.1 Watershed Description 1.2 Geology, Vegetation and Fauna 1.3 History of the Auke Lake Watershed 2. Hydrology, Water Rights and Wetlands 2.1 Auke Lake and Auke Lake Tributaries 2.2 Surface and Ground Water Rights 2.3 Wetlands 3. Fish and Fisheries Habitat 3.1 Fish Populations 3.2 History of Fish Propagation 3.3 Habitat Condition Summary 4. Water Quality 5. Land Use and Lake Management 5.1 Land Ownership 5.2 Land Use Designations 5.3 Zoning 5.4 Lake Management 5.5 Proposed Development in the Watershed 6. Community Uses of the Auke Lake Watershed 6.1 Auke Lake User Survey 6.2 Motorized Watercraft on Auke Lake 6.3 University of Alaska Southeast (UAS) 7. Watershed Condition Summary 8. Watershed Protection and Enhancement Opportunities 9. References 8. Appendices
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List of Figures

Figure 1:

Auke Lake Watershed Location and Boundary………………pg. 6

Figure 2:

Mean Monthly Depth at the Auke Lake UAS

Dock and Mean Monthly Discharge for Auke

and Lake Creek………………………………………………pg. 8

Figure 3:

Mean Monthly Discharge for Auke and Lake Creeks,

Mean Monthly Snowfall and Precipitation……………………pg. 9

Figure 4:

National Wetlands Inventory Wetland Types in the Auke

Lake Watershed……………………………………………...pg. 11

Figure 5:

Auke Lake Anadromous Streams……………………………pg. 13

Figure 6:

Auke Lake Watershed Channel Types and Fish Utilization

Map…………………………………………………………pg. 17

Figure 7:

Auke Lake Watershed Ownership…………………………...pg. 20

Appendices Appendix A: Appendix B: Appendix C: Appendix D: Appendix E: Appendix F: Appendix G:

Surface Water Rights Reserved in the Auke Lake Watershed Auke Lake Watershed Channel Process Types and Management Considerations Available Water Quality Data for Auke Lake and its Tributaries Auke Lake State Land Use Designations Definitions of Land Use Designations in the Auke Lake Watershed Auke Lake Public Meeting Notes Auke Lake Watershed Assessment Community Survey Results

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1. INTRODUCTION
1.1 Watershed Description Auke Lake is a freshwater lake located approximately 12 miles north of downtown Juneau, Alaska (Figure 1). Oriented roughly northwest to south, the watershed encompasses approximately 2,558 acres, with elevations ranging from sea level to just over 2,000 feet. The Auke Lake watershed drains into an area of approx. 2, 500 acres (Bethers, 1995), and is bounded by the mouth of Auke Creek in Auke Bay, the headwaters of Lake Creek, Goat Hill, and Peterson Hill.
Auke Lake itself covers a surface area of approximately 177 acres and has a maximum depth of 113 feet (Bethers, 1995). The lake surface rises 56 feet above sea level and the forested shoreline consists of a mix of gentle slopes and steep-sided banks (Lum and Taylor, 2006).
1.2 Geology, Vegetation and Fauna Geology A combination of tectonic forces and glacial activity formed the Auke Lake watershed (Monteith, 2007). Area geology consists primarily of glacial, glacio-marine, and alluvial deposits overlaying a northwest trending belt of metamorphosed volcanic and sedimentary bedrock (Brew and Ford, 1985).
Between 10,000 to 12,000 years ago, Auke Lake was part of a marine embayment that extended southwest to Pederson Hill and northwest to Goat Hill. Isostatic rebound lifted the landmass in the area around 6,500 years ago, transforming the lake into a salt chuck with salt water entering the lake during high tides. Auke Lake stabilized at its current elevation of approximately 56 feet above sea level some time within the last 6,000 years (Monteith, 2007).
The Mendenhall Glacier advanced four kilometers during the Neoglacial or Little Ice Age (3,000-250 years ago) but the terminal glacial moraine did not extend into the Auke Lake watershed. However, the bathymetric model created by Connor et al. in 2006 demonstrates a U-shaped lake basin in both the northsouth and east-west profiles, indicating repeated advances of the Mendenhall Glacier into the Auke Lake watershed at some point in time (Monteith, 2007).
Vegetation The Auke Lake watershed is forested primarily with Sitka spruce and western and mountain hemlock, with alder species found adjacent to streams and wetlands. Spruce trees began growing on the terminal moraine near the watershed boundary on Back Loop Road by the late 1700s (Montieth, 2007). Trees on the east side of the lake are primarily uneven-aged old growth including some large spruce trees. Wind influences the forest structure around Auke Lake, leaving the exposed, mostly southeast facing slopes dominated by evenaged hemlock trees. (Carstensen, 2007)
Typical understory vegetation includes shrubs such as Devil’s club, blueberry, and salmonberry as well as herbaceous plants including ferns and skunk cabbage. Wetland plant species indicative of emergent wetland habitats are primarily located in the upper watershed along the Lake Creek system while estuarine wetland plants grow near the mouth of Auke Creek. Emergent vegetation such as horsetail and pond lily dominate some areas along the lake shoreline. Submerged and floating conifers are anchored to the bottom by large root wads along much of the lakeshore. (Lum and Taylor, 2006).
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Figure 1: Auke Lake Watershed Location and Boundary. -6-

Birds and Wildlife Mallard, merganser, belted kingfisher, great blue heron and red-throated loon regularly use the Auke Lake watershed. Robin, varied thrush, Steller’s jay and winter wren frequent the Little Auke Creek area, and hermit thrush and junco live in the muskeg area near Lake Creek (Adamus et al., 1987). Sandhill crane, bald eagle, Canada geese, and trumpeter swans also use the area.
Beavers and river otter have been sighted in and around Auke Lake. Sitka black-tailed deer and black bear also frequent the area. Other mammals common to forested habitats in the Juneau area likely to inhabit the watershed include porcupine, marmot, red squirrel, and voles. Wolves have been observed near Mendenhall Lake and likely travel through the Auke Lake watershed to Peterson Creek.
1.3 History of the Auke Lake Watershed Auke is a derivative of the Tlingit word for “little lake,” or “Aak’w.” The Auk’w Kwaan is one of fourteen Tlingit tribes in Southeast Alaska and resided near the lake in historic times (Monteith, 2007). The traditional territory of the Auk’w Kwaan encompassed the north end of Admiralty Island, Douglas Island and the mainland from Juneau north to Berners Bay (Chandonnet, 2002).
The Auk people landed in Auk Bay around 1564 and occupied a village and fish camp along Auke Lake where the campus of the University of Alaska Southeast (UAS) now resides (Monteith, 2007). Researchers and students from UAS conducted an archaeological survey of Auke Lake in 2006 and 2007 and found 9 culturally modified trees around the lake, as well as charcoal and other artifacts from pre-European contact.
Early European settlers called the lake “Aylward Lake”, after Ed Aylward who staked mining claims in the area in 1884. The lake is first referred to by the name Auke Lake in records from 1902, when William Winn and N.A. Needham claimed it for a fish hatchery site (Mobley, 1992).
The Auke Bay District gold rush began when Tom Dull and John Stephens announced a new discovery site “just north of Auke Bay” in August, 1908. Prospectors staked claims throughout the Auke Bay area, a few of which were successful small-scale operations. The Stephens and Dull claims are situated on Lake Creek near the confluence of its southernmost tributary. Victor Spaulding was among the prospectors who worked the Treasury Hill group of claims, located near the watershed boundary between the Lake and Wadleigh Creeks. Both panning and tunnel blasting were conducted, and there were several abandoned mine shafts in the watershed (Redman, 1988).
Road and trail development in the Auke Lake watershed intensified in 1908 and 1909 when a wagon and foot trail was built between downtown Juneau and Eagle Creek. Glacier Highway was extended to Auke Bay between 1914 and 1918, and a bridge over the Mendenhall River was constructed in 1916. Road and bridge development over Auke Creek likely wiped out archeological evidence of Auk fish camps where the creek drains from the lake. Back Loop Road was built in 1921 (Monteith, 2007) and was reconstructed in 1968. (Taylor and Wing, 2008).
2. HYDROLOGY, WATER RIGHTS, AND WETLANDS
2.1 Auke Lake and Auke Lake Tributaries Auke Lake is the largest non-glacial lake on the Juneau road system. The lake water is generally clear with a brownish tint. Mud is the primary lake substrate, with some gravel areas located at the stream inlets (Bethers, 1995). Water depth measurements taken at the University of Alaska Southeast dock in 2006 and 2007 show some fluctuation in lake level somewhat correlated with mean monthly discharge data for Auke and Lake Creeks (Figure 2).
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3

35

Mean monthly depth (ft) Mean monthly discharge (cfs)

2.5

30

25 2

20

Lake Depth

1.5

Auke Cr. Discharge

15

Lake Cr. Discharge

1 10

0.5

5

0

0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Figure 2: Mean monthly depth at the Auke Lake UAS dock and mean monthly discharge for Auke and Lake Creeks. Lake depth measurements taken when the lake was ice free, May 2006 through November 2007 (Hood and Jacobs, unpublished data). USGS data period of record for Auke Creek: 1947-1975; for Lake Creek: 1963-1973.

The lake freezes over each winter and has both fall and spring turnover events, when the entire water column mixes as a result of changing temperature gradient. Observations of lake freezing and thawing since 1961 show a general trend toward earlier ice-out, though not at a statistically significant rate (Taylor, 2007). Midwinter breakup events followed by refreezing occurred in 2000, 2001, and 2003 (Wing et al., 2006).

Lake Creek is the largest of the six inlet streams that enter the lake on the north and west shores of Auke Lake. Smaller streams include Lake Two Creek (also known as Little Auke Creek), and the unofficially named UAJ, MB and Hanna Creeks (Bethers, 1995). Auke Creek is the only outlet stream for Auke Lake and enters saltwater at Auke Bay.

U.S. Geological Survey (USGS) discharge data is only available for Lake Creek and Auke Creek. Mean monthly discharge for the two creeks is correlated, and the peak discharge for both creeks occurs in May. Precipitation data show discharge for Lake and Auke Creeks is correlated with rainfall in late summer and early fall, while the spring peak discharges are likely a response to snowmelt (Figure 3).

Lake Creek is the primary tributary to Auke Lake and drains approximately 3.5 square miles of undeveloped forestland. The creek’s main channel is 3.6 miles in length with a total of 6 miles of stream. Its headwaters rise nearly 1700 feet in elevation in a substantial forested/shrub wetland complex locally known as ‘Spaulding Meadows’. The streambed substrate is mostly composed of gravel with some bedrock, with a fish passage barrier falls located approximately 1.25 miles upstream from the mouth (Bethers, 1995).

Lake Two Creek (also known as Little Auke Creek) is a small drainage of approximately 1 square mile located east of Lake Creek. Most of the land draining into both Lake and Lake Two Creeks is largely undeveloped. Back Loop Road crosses both streams approximately 600 feet upstream from their lake outlets.

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Discharge (cfs) Precipitation (in.)

35.00

10.00

9.00

30.00

27.58

8.00

25.00 20.00 15.00 10.00

17.57 11.38

7.00 20.87 6.00
5.00
11.81 4.00 3.00

2.00

5.00

2.28

1.00

0.05 0.00 0.00 0.00 0.02 0.60

0.00

0.00

Jan Feb Mar Apr May Jun

Jul

Aug

Sep

Oct

ov N

ec D

Snowfall (in.) Lake Creek Auke Creek Precipitation

Figure 3: Mean monthly discharge for Auke and Lake Creeks, mean monthly snowfall and precipitation. Snowfall and precipitation data collected at the NMFS Auke Bay Laboratory, 1963-1993 (Wing and Pella, 1998). USGS data period of record for Auke Creek: 1947-1975; for Lake Creek: 1963-1973.

Auke Creek is a lake-fed outlet stream that flows about 0.3 miles from Auke Lake into Auke Bay (Wing et al., 2006). Water flowing into Auke Creek passes through a shallow lagoon, and a narrow channel with a bedrock sill and water depth often less than 8 inches. The Glacier Highway crosses over Auke Creek just below the lake outlet. Experimental spawning beds were installed by National Marine Fisheries Service (NMFS) in the upper section of Auke Creek, but otherwise the substrate is primarily bedrock and small boulders or cobbles. A concrete flume adjacent to the creek supplies water to the NMFS Auke Bay Laboratory (Kramer, Chin & Mayo, Inc., 1978). A weir has been in place approximately 0.25 miles downstream from the lake since 1961 (Bethers et al., 1995; Lum and Taylor, 2006).

2.2 Surface and Ground Water Rights Surface and groundwater rights are reserved throughout the watershed. Water rights permits are adjudicated by the Alaska Department of Natural Resources (ADNR), and have been issued to federal and state agencies and private citizens who own land on Auke Lake, Auke Creek, Lake Creek, and Little Auke Creek (Appendix A). There are three surface water rights in the Auke Lake watershed for household use and three substantial withdrawal permits held by NMFS and the Alaska Department of Fish and Game (ADF&G) for use in research and hatchery operations. ADF&G also holds instream flow reservations for Auke and Lake Creeks, which vary in flow rates throughout the year in order to maintain minimum flows for fish habitat.

The ADNR water rights database has 20 subsurface rights on record, primarily held by citizen landowners around Auke Lake. At least one subsurface right is listed as being permitted to an individual but is slated for use by the NMFS lab and domestic facilities (ADNR, no date). All of the subsurface rights applications were initiated and all but two were permitted prior to the extension of city water lines to the area in 1986 (Lowery, 2008).

2.3 Wetlands There are multiple wetland areas within the Auke Lake watershed. Wetlands designated by the U.S. Fish and Wildlife Service (USFWS) National Wetland Inventory (NWI) do not necessarily coincide with those identified and classified by CBJ. This is partly due to the scope of CBJ’s wetland assessment, which does not
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include federal lands within the Borough boundaries. CBJ also used U.S. Army Corps of Engineers maps, combined with field-truthing on a subset of wetlands included on the maps, in order to establish its wetland management plan (CBJ, 1997). The NWI has a much broader scope and uses aerial photography and USGS 1:24,000 topographical maps as a basis for regional or watershed analyses (USFWS, 2007). CBJ Wetlands CBJ wetlands designations are based upon three factors: 1) the evaluated environmental functions of each wetland unit, 2) the availability of practicable upland alternatives to wetlands development, and 3) a survey of public preferences for the management of wetland units. Designations range from Class A, wetlands of the highest value which are least suitable for development, to Class D wetlands that are more suitable for development (CBJ, 1997). In the Auke Lake watershed, there is a substantial Class A wetland situated along and adjacent to Lake Two Creek. Two smaller Class A wetlands associated with UAJ and MB Creeks on the north side of the lake are located within a larger Class B wetland to the west of Lake Creek. Five Class C wetlands are scattered around Auke Lake, and there are no Class D wetlands identified in the watershed (CBJ, 1994). National Wetland Inventory Most of the wetlands in the Auke Lake area are forested or shrub type freshwater wetlands, with a few small freshwater emergent wetlands scattered across the northern portion of the watershed (Figure 4). A marine/estuarine wetland is situated at the mouth of Auke Creek (USFWS, 2007). Wetlands in the Auke Lake watershed function primarily as recharge zones, or “have groundwater moving laterally,” according to the Juneau Wetlands Functions and Values report (Adamus et al., 1987).
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Auke Lake Watershed Assessment