Little Averill Lake: Where Heaven Meets Earth
Looking for potential sources of the increase in Total Phosphorus in an oligotrophic lake in the Northeast Kingdom of Vermont.
Early Fall Foliage at Little Averill Pond, Vermont 9/11/17
“Little Averill Lake is surrounded by northern hardwood forest, some mixed hardwood-softwood forest, and an unusual natural lake sand beach. Ridges and mountains border the north, west, and south shores of this kidney-shaped lake, thus giving an amphitheater effect" (Mills, 1951).
Little Averill is a ~470 acre lake, with a maximum depth of 116 feet, and a total volume of over a billion cubic feet of water. The water level of Little Averill Lake is under a complex multinational and multi-jurisdictional framework as it serves as the headwater for hydro-electric production and flood prevention for Coaticook, Quebec, Canada.
Little Averill Lake is drained via a key tributary of the Coaticook River - Averill Creek - which flows northeast out of Little Averill into Big Averill Lake and then northwest out of Big Averill into the Coaticook.
The water levels are controlled by the Coaticook River Water Power Company in Coaticook, Quebec, Canada through a series of control dams on the Averill Lakes as well as Norton Lake but within parameters established by the State of Vermont's Public Utility Commission (30 V.S.A. § 404).
Little Averill Lake is surrounded by more than 84,000 acres of timberlands owned, managed, actively forested by Weyerhauser and a conservation reserve managed by The Nature Conservancy (VTANR, 2014).
All privately owned camps on Little Averill Lake are off the grid and are only accessible by foot during mud season (which may be a 12+ mile round trip hike from the entrance on VT114.
“I think about all lakes that once were like Little Averill, but are now stressed by nutrient enrichment, aquatic invasive species and degraded shoreline habitat. Ultimately, Little Averill reminds me there are still high quality lakes out there that can be saved. While there are few left, that makes them all the more worth saving.”
Kellie Merrell, Aquatic Ecologist Vermont Agency of Natural Resources, Department of Environmental Conservation Watershed Management Division, Lakes and Ponds Management and Protection Program
Little Averill was classified ultra-oligotrophic in the early 1980s, a trophic condition that is unique for its rarity in Vermont. However, the annual Spring annual mean for Total Phosphorus (TP) has a statistically significant increasing trend, within a watershed that had historically low TP and minimal human disturbance With an increasing number of property transfers, new camps being developed, dirt roads being extended, and more active forestry operations, the State of Vermont's Agency of Natural Resources' Department of Environmental Conservation was concerned with the potential impacts from those land use practices to this unique and very special lake.
A one time assessment conducted by the Vermont Agency of Natural Resources (VTANR, 2013) found higher than expected TP levels in some of the tributaries draining into this ultra-low nutrient lake. Merrell and Matthews (2020) postulated forestry operations and/or camp roads may be the source of rising TP impacting water quality on Little Averill Lake
With the enthusiastic support and sponsorship of the State of Vermont's Lake and Ponds Program and Aquatic Ecologist Kellie Merrell in particular, Little Averill Lake was accepted into the State of Vermont’s LaRosa Partnership (LPP) program for water quality monitoring on the 3 inbound tributaries of Little Averill Lake to see if they may be contributing to the rise of Spring TP in the Lake. Three members of the Averill Lakes Association volunteered to be Citizen Scientists and were trained and certified in the LPP program - Bernie Gracy, Connie Jackson, and Susan Gresser.
The aim of the LaRosa Partnership Program is to provide meaningful water quality monitoring data to various State of Vermont and Little Averill Lake stakeholders through community scientists who know the watershed (VTANR, 2022). An example of applying that knowledge is sampling Inlet 2 a bit upstream under a bridge as to not disturb nesting loons at the inlet's outlet to the Lake. The LPP aims to characterize and fill in data gaps in the water chemistry component of stream health by focusing on 4 water quality monitoring categories:
1) identifying potentially high-quality waters 2) sampling lake tributaries that may be contributing to phosphorus loading in lakes 3) identifying stressed or impaired waters and refining the extent and/or source of the stressor 4) evaluating the effectiveness of Best Management Practices (BMPs) or other remediation efforts. (VTANR, 2022).
The sampling season runs officially from April 16th to August 8 with the goal of capturing 8 sampling events and 2 high flow events (e.g. after ice out or a rain event). But Little Averill was inaccessible until Mid-May due to mud season. Sampling began immediately after Weyerhauser and the Averill Camp Owners Association opened up Averill Lake and East Branch roads to traffic.
TP and TN samples were collected at all 3 tributaries (including field duplicates and lab duplicates) using the prescribed methods and quality controls provided by the LPP . Stream flow was characterized and geotagged pictures taken upstream and downstream at each survey location. ESRI's Survey123 mobile app was was used to associated the sample identifiers, the sampler name, the location, time and date, flow characterization, and the photos with all of the digital data uploaded to the LPP program via the citizen scientist's iPhones and/or iPad. Field data was also captured on paper forms provided by the LPP.
The samples and associated data sheets were processed and stored at the Lake View Store in Norton Vermont for later pickup by LPP staff. LPP staff then brought the samples to the Vermont Agriculture and Environmental Laboratory (VAEL) in Randolph Vermont for processing.
The 2022 sampling season data and preliminary TP and TN results (subject to final quality control verification) can be explored in the subsequent interactive map.
2022 Tributary Sampling of TP and TN on Little Averill Lake
As compared to the single day sample taken by the State of Vermont in August of 2013 for each of the Inlets - the results are remarkably consistent in proportion to each other and historically for each Inlet at the end of the sampling period. An intriguing question is why the steady increase in TP in Inlet 1 and then a radical drop-off to its presumed "normal range?"
The sampling on June 8th and June 18th were taken after periods of heavy rain which is when the steady increase in total phosphorus began. Note the same rain events had no material effect on Inlets 2 and 3.
A material change in TN was also noted in the same period as the rise in TP and with the same substantial fall off.
Next Steps: The 2022 LaRosa Partnership Program sampling on Little Averill Lake points to Inlet 1 as a potential source of TP but more data is required. As such, the Averill Lakes Association has requested to be selected again for the 2023 season. In addition the Lakes and Ponds Program plans to deploy a continuous sensor buoy at the Deep Hole in Little Averill Lake in 2023 to measure dissolved oxygen, temperature, and water levels. This Story Map and supporting ArcGIS maps will be maintained and updated when additional data is available.
The elevated levels of TP and TN in Inlet 1 between the beginning of June to mid-July with respect to the other Inlets may point to potential non-point sources of pollution based on catchment characteristics such as slope, drainage area, and wetlands. D'Arcy and Carignan (1997) posit from a study of lakes in nearby southeastern Quebec that there is a strong influence of catchment slope on water quality due to slope-dependent seasonal waterlogging, which determines the retention or export to surface waters of dissolved substances produced within and moving through the forest floor. Inlet 1 also discharges into a very shallow area on Little Averill Lake. This raises additional questions on the potential effects of hydrodynamic, wind, and wave processes for not only the transport of the TP coming out of Inlet 1 to the rest of the lake - but potentially the resuspension of TP from shallow sediments of past depositions being pushed into Inlet 1 during our sampling. There has also been substantial beaver activity around Little Averill - in particular just outside the perimeter of the watershed near Inlet 1 off of East Branch Road. Devito and Dillon (1993) postulate that the accumulation of flooded forest material and input of organic matter by beaver may be very important to P and N dynamics, representing a long-term source of nutrients to pond water and outflow.
Hence a more detailed survey and study of the geomorphology and soils/wetlands of the catchment, the dynamics of TP deposition in shallow lake waters, as well as the potential of beaver activity within the watershed behind Inlet 1 is also warranted. Finally is it important to note the complexity of attempting to correlate the rise in Annual Mean Spring TP solely through the contribution of Little Averill Lake's tributaries. As noted above the lake level is under the control of the Coaticook River Water Power Company. Shantz, et al. (2004) demonstrated that lake drawdown also contributes to a rise in TP. The continued partnership, collaboration, and vigilance of citizen scientists, the Averill Lakes Association, the State of Vermont, Weyerhauser, and numerous other stakeholders, beneficiaries, and community groups are required to monitor and protect this very special lake in the Northeast Kingdom of Vermont. As an ALA Board member recently commented - "The Averills are where Heaven meets Earth." Sincere Appreciation and Recognition
My deep thanks to Kellie Merrell of the Lakes and Ponds Management and Protection program for her support and advocacy of this work and of the Averill Lakes; Mel Auffredou of the Watershed Management Division, Monitoring and Assessment Program and the 2022 LPP Program Coordinator; Doug Morin of Vermont Fish and Wildlife; my fellow citizen scientists Dr. Susan Gresser, Connie Jackson, and Don Tase; the Rich and Cowan families who graciously let us use their property to take samples; David Leidy of the Lake View Store in Norton Vermont who allowed us to acidify, refrigerate, and store our samples, supplies, and equipment on his premises; the support of the board and leadership team of the Averill Lakes Association; the support, sponsorship, and guidance of Dr. Eric Holmlund, Dr. Ellen George, and Dr. Brendan Wiltse of Paul Smith's College; and especially Dr. Melanie Johnson, Professor of Environmental Science, GIS, and Remote Sensing at Paul Smiths College.
Data Sources:
2022 LaRosa Partnership Program Data - A read-only view of the LaRosa Partnership Program flow observations, water sample metadata, and photographs submitted by LaRosa partners from the field in the 2022 sampling season. Coordinate System: WGS 1984 Datum: D WGS 1984 Retrieved from https://vtanr.maps.arcgis.com/home/item.html?id=6f468148c74b40cca77dca718156c5f4 2022 LaRosa Partnership Program Lab Results - TP and TN lab results associated with water samples and water sample metadata captured by LaRosa partners from the field.
Received through automated e-mail distribution from the Vermont Agricultural and Environmental Laboratory's WinLIMS Laboratory Information Management System.
Vermont Bathymetric Data - Table showing depth and location for various lakes and ponds in Vermont including Little Averill Lake (Note water depth is relative to pool elevation at the time of collection) Coordinate System: WGS 1984 Datum: D WGS 1984 Retrieved from https://geodata.vermont.gov/datasets/b152a736dccc40b7a67ea2dc007500b0_0/explore Vermont Protected Lands - Parcels protected from development through public ownership, private ownership, or easements. Coordinate System: NAD 1983 StatePlane Vermont FIPS 4400 Units: Meters Datum: D North American 1983 Retrieved from https://maps.vcgi.vermont.gov/arcgis/rest/services/EGC_services/OPENDATA_VCGI_CADASTRAL_SP_NOCACHE_v1/MapServer Vermont Zoning - Averill - Shapefile containing zoning boundaries for commercial, industrial, and residential; forest land, agricultural, and single family homes; shoreland, and water. Coordinate System: WGS 1984 Datum: D WGS 1984 Retrieved from https://geodata.vermont.gov/datasets/6851ee61b40047e5a2f5adc62ad2dd6b/about
References: D'Arcy, P., & Carignan, R. (1997). Influence of catchment topography on water chemistry in southeastern Quebec Shield lakes. Canadian Journal of Fisheries and Aquatic Sciences, 54(10), 2215-2227. Devito, K. J., & Dillon, P. J. (1993). Importance of runoff and winter anoxia to the P and N dynamics of a beaver pond. Canadian Journal of Fisheries and Aquatic Sciences, 50(10), 2222-2234. Merrell, K. and Matthews, L. (2020, August 13). Little Averill Lake Water Quality Trends. Virtual Presentation to Little Averill Camp Owners. Mills, J. (1951) A Study of Lakes in Northeastern Vermont. Vermont Development Commission. Retrieved from https://anrweb.vt.gov/PubDocs/DEC/GEO/Bulletins/Mills_1951_1.pdf
Rowe, J. (2017, September 11). Early Fall Foliage at Little Averill Pond. Retrieved from https://www.youtube.com/watch?v=PfyA2JBgtVs
Shantz, M., Dowsett, E., Canham, E., Tavernier, G., Stone, M., & Price, J. (2004). The effect of drawdown on suspended solids and phosphorus export from Columbia Lake, Waterloo, Canada. Hydrological Processes, 18(5), 865-878. Vermont Agency of Natural Resources (2013, August 21). Little Averill Lake Assessment. Retrieved from https://anrweb.vt.gov/PubDocs/DEC/WSMD/Lakes/NextGenerationLakeAssessmentReports/LITTLE%20AVERILL_2013_1_342.html#inlets
Vermont Agency of Natural Resources (2014, September). Long Term Access Plan for the Private Timberlands Portion of the Kingdom Heritage Lands. Retrieved from https://fpr.vermont.gov/sites/fpr/files/State_Lands_Administration/Lands_Management_Planning/Library/KingdomHeritagePublicAccessPlan.pdf
Vermont Agency of Natural Resources (2020). Vermont State Scorecard - Little Averill Pond. Retrieved from https://anrweb.vt.gov/PubDocs/DEC/WSMD/Lakes/Lake_Score_Cards/LITTLE%20AVERILL.HTML
Vermont Agency of Natural Resources (2022). LaRosa Partnership Program Model. Retrieved from https://dec.vermont.gov/watershed/map/monitor/larosa/programmodel
