Lake Whatcom Update — Are We Making Progress?

by April Markiewicz

In the Harry Potter world, all that is needed to summon fresh, clean water is a magical wand and incantating “aquamenti.” In our non-magical world, however, many of us just rely on turning on a water tap. It’s a different form of magic based on science and technology. We don’t give any thought about where the water comes from or what efforts and resources were invested to bring that water to our fingertips.

We automatically assume our tap water is clean even though we may not recognize it is due to federal, state, and local laws that ensure the quality of the water meets or exceeds their respective water quality criteria.

So where does our vital, clean water come from in Whatcom County? It comes from Lake Whatcom, that recreational destination so highly publicized in real estate newsletters and on multiple websites welcoming tourists to enjoy the many services it provides.

Contrary to common sense and best management practices, we allow people to continue building homes and living in its watershed, harvesting timber from the surrounding hillsides, landing float planes on its surface, allowing the use of gas-guzzling (and fuel-leaking) jet skis and motorized boats on it, in addition to swimming, fishing, bathing, and relieving ourselves in it as well.

Bottom line is we treat our community’s vital drinking water source as a tourist attraction and as our own personal bathtub and toilet. And because of our actions, we have the added “benefit” of paying to “clean up” the water to meet federal, state, and local water quality criteria to make it safe for us to use and drink.

Map - Lake Whatcom

Lake Whatcom watershed and subbasins (Strecker et al., 2021).

About the Lake

Lake Whatcom is our community’s main source of drinking water for approximately 100,000 residents, not only in the City of Bellingham (city) and surrounding communities, but throughout Whatcom County as well.

The lake itself was created more than 10,000 years ago through glacial activity and is comprised of three subbasins (see map in middle column of this page) that extends from the northeast section of the city south into Whatcom County and includes the resort community of Sudden Valley. Each subbasin is separated by underwater sills that affect water currents, transport, quality, and flow between the basins.

Since the early 1900s, water quality studies indicated that the lake was showing signs of decline due to human activities in the watershed. Specifically, from logging, timber milling, mining, residential development, and recreational activities. By the 1960s when the city transitioned to having Lake Whatcom as its primary drinking water source (rather than Lake Padden), further studies revealed water quality degradation was accelerating. The lake was becoming more biologically productive due to human activities allowed in its watershed.

By the late 1980s, further concerns about water quality in the lake resulted in the establishment of the Lake Whatcom Monitoring Program by the City of Bellingham to provide long-term baseline water quality data. The city contracted with Western Washington University’s Institute for Watershed Studies (IWS) to have them take the lead in the monitoring program.

Those studies provided irrefutable evidence that over time the lake’s water quality was steadily declining and no longer meeting water quality standards for dissolved oxygen (DO) and bacteria. The culprit for the low DO was found to be too much phosphorus entering the lake from the surrounding watershed.

Those data are now used by City of Bellingham, Whatcom County, and Lake Whatcom Water and Sewer (LWWS) staff to develop five-year work plans to help prioritize the allocation of funding, staffing, and resources to prevent phosphorus entering the lake. The main source of phosphorus into the lake is via untreated stormwater runoff from impervious surfaces in the watershed.

The first work plans focused on installing stormwater treatment vaults throughout the residential areas located around the north end of the lake. The city recently completed that work and three jurisdictional parties are now focusing on other threats to the lake.

Ten program areas were identified to target, of which Land Preservation, Stormwater, Aquatic Invasive Species, and Education & Engagement were prioritized. These programs are not cheap, and, in 2023, the cost was over $11 million.

Where We Are Today

Efforts to halt the decline in Lake Whatcom’s water quality are now managed by an interjurisdictional Lake Whatcom Management Team comprised of the City of Bellingham, Whatcom County, and Sudden Valley’s Lake Whatcom Water and Sewer District.

At the team’s Joint Councils and Commissioners (JCC) meeting on March 27 of this year, the most recent data on the status of Lake Whatcom’s water quality, as well as progress on meeting the goals outlined in the Lake Whatcom Management Program (LWMP) 2020-2024 Work Plan, were presented.

These meetings are held annually and provide an opportunity for the JCC and the public to learn about and comment on the status of our community’s primary drinking water source.

What the Data Show

The efforts of the Lake Whatcom Management Team over the last 20-plus years appear to be making a difference. The water quality data presented in the most recent 2022/2023 Lake Whatcom Monitoring Program Annual Report show that the rate of water quality degradation has been slowing down, especially during the last decade. Moreover, some water quality parameters are either remaining relatively unchanged (flatlined) or slightly improving (Strecker et al., 2024).

Water quality conditions in the lake in 2023 were as follows:

  • Due to cooler spring and early summer weather conditions, water temperatures were lower through May, but within historic ranges. This resulted in a slight delay in thermal stratification until the end of May in basins 1 and the north end of 3 and by early June in basins 2 and the south end of 3.
  • DO (dissolved oxygen) concentrations in the bottom waters of basin 1 were higher than in previous years. Strecker et al. (2024) were surprised to find the DO concentration at 14 meters in July to be above 5 mg DO/L. Historically, it is usually at about 4 mg DO/L (see Figure 1). Moreover, in August, concentrations were still at 3 mg DO/L rather than the typical 1 mg DO/L. By September, however, DO concentrations were at 0 mg DO/L.

Dissolved Oxygen

Figure 1. Trends in dissolved oxygen over time in basin 1 at 14 meters
(~46 feet) sampled in July, August, and September from 1988 through
2023 (Strecker et al., 2024).

  • Chlorophyll (Chl) concentrations, a direct measure of algal biomass and indicator of a lake’s biological productivity, appear to be trending up these last 2 years in basins 2 and 3, but trending down in basin 1. Strecker et al. (2024), however, states that the concentrations have leveled off since 2004 (see Figure 2).

Figure 2. Median summer near-surface chlorophyll concentrations
(June – October) at each sampling site from 1994 – 2023, depths ≤
5m) (Strecker et al., 2024).

  • Green algae (Chlorophyta) and Cyanobacteria numbers are variable; however, they appear to be gradually increasing throughout the lake except for last year (see Figure 3 and Figure 4). Strecker et al. (2024) noted they dominate the plankton biomass in late summer and early fall. Moreover, based on rapidly declining dissolved inorganic nitrogen in the lake every summer, water quality conditions may “… become favorable for the growth of nitrogen-fixing Cyanobacteria …”, many of which are toxic to wildlife, pets, and humans. Monitoring of the types of Cyanobacteria present in the lake is now ongoing.

Chlorophyta and Cyanobacteria

Figure 3. Log 10 plots of median summer near surface green algae
(Chlorophyta) counts from June through October at all sites and depths
(1994 – 2023) (Strecker et al., 2024).
Figure 4. Log plots of median summer near surface Cyanobacteria
counts from June through October at all sites and depths (1994 – 2023)
(Strecker et al., 2024).

  • Total phosphorus (TP), a required nutrient for algal growth, was still measurable in the surface waters of basin 1, indicating potential ongoing inputs into the basin. In basins 2 and 3, however, TP was below analytical detection limits, indicating potentially less inputs, as well as its rapid biological uptake and utilization (see Figure 5). In the bottom waters, TP is elevated in both basin 1 and 2 during the summer when DO is low.
Total Phosphorus

Figure 5. Median summer near-surface total phosphorus concentrations
at each sampling site from 1994 – 2023, depths ≤ 5m) (Strecker
et al., 2024).

  • Dissolved inorganic nitrogen (DIN), like phosphorus, is a nutrient required for algal growth and an indicator of biological productivity. DIN concentrations in the surface waters during the summer continue to rapidly decline and were below or at analytical detection limits in basins 1 and 2 (see Figure 6). The decline has been attributed to the increase in lake productivity. Of note by Strecker et al. (2024), DIN in basin 1 has been below analytical detection limits during the summer since 2004, whereas it wasn’t until 2019 that DIN dropped below or slightly above detection limits in basins 2 and 3 during the summer. This is an indication that productivity is continuing to increase in those two basins.
Dissolved Inorganic Nitrogen

Figure 6. Minimum summer near-surface dissolved inorganic nitrogen
(DIN) concentrations at each sampling site from (June – October)
1994 – 2023, depths ≤ 5m) (Strecker et al., 2024).

Long- and Short-Term Trends

Looking at each figure, it is important to remember that each point represents one year’s worth of data. Variations from year-to-year are not only a function of human activities in the watershed and the amounts of nutrients entering the lake, but also the responses of the lake’s biological organisms to those nutrients under changing environmental conditions, including variations in weather and temperature, type and amount of precipitation, wind patterns, cloud cover, and water currents, as well as interactions within and between species in the lake.

The trends in the data for the last few years have been more encouraging, showing that for some of the water quality indicators, the data have stayed relatively unchanged (i.e., have flatlined according to the presenters at the JCC meeting) or are trending downwards. Moreover, even those data that are still trending up seem to be doing so at a slower rate of increase (Strecker et al., 2024).

Are We Making Progress?

That is the question asked by Councilmember Michael Lilliquist of his fellow city and county elected officials and commissioners, as well as the staff during the meeting on March 27. There have been decades of efforts, resources, and funding invested in trying to halt the decline of Lake Whatcom, however, he has not seen progress towards significantly improving water quality in the lake.

He noted that some of the data show those efforts may have made a difference in protecting Lake Whatcom from more severe impacts to its water quality. There are no data, however, that explicitly show we are making progress in restoring the lake to conditions mandated in the Washington Department of Ecology’s Total Maximum Daily Loading (TMDL) report for Lake Whatcom. Councilmember Lilliquist’s question went unanswered.

Those efforts, resources, and funding are summarized in 2023 Lake Whatcom Management Program Progress Report (LWICT 2023) for the 10 program areas of the Lake Whatcom Management Program (LWMP) 2020-2024 Work Plan. The report includes the 2023 activities, accomplishments, reporting metrics and expenditures. In brief those program accomplishments are:

  1. Land Preservation: 12,596 acres in the watershed have been protected to date.
  2. Stormwater: 90 stormwater treatment facilities have been installed and maintained.
  3. Land Use: 13 acres of phosphorus-neutral properties have been developed or redeveloped since 2009, with 18 acres of timber harvested and replanted.
  4. Monitoring and Data: Over 1,100 water quality samples were collected in 2023.
  5. Hazardous Materials: 151 new staff were trained in spill prevention and response in 2023. A total of 16 spills were reported.
  6. Recreation: 1.5 miles of new trails were built, 22 miles of trails were maintained, and 30 pet waste stations were maintained.
  7. Aquatic Invasive Species: 14,233 boats were inspected, 1,324 boats had standing water in them and had to be drained, 103 boats had aquatic plants that had to be removed, and 12 boats were decontaminated for invasive mussels.
  8. Utilities and Transportation: 413,000 gallons of water were conserved with water use efficiency measures, including residential water use restrictions.
  9. Education and Engagement: A total of more than 13,700 people were engaged in 2023 – utilizing the LWMP website, receiving the newsletter and e-newsletter, participating in the Water School Program, and attending the Lake Whatcom Wildfire Risk Reduction workshops.
  10. Administration: held 3 Lake Whatcom Policy Group meetings and 10 interjurisdictional Coordinating Team meetings.

In the 2025-2029 Work Plan, a Climate Action program will be added and a Climate Vulnerability Study will be conducted.

Other Concerns

During the public comment period of the meeting, a wide range of concerns were presented to the JCC and staff. They included:

  • The fact that development is allowed to continue in the watershed with 31 new homes being built last year. No studies have been done to determine the amount of phosphorus coming from those properties.
  • Mill Creek properties have not been retrofitted and continue to discharge untreated pollutants into the lake.
  • Changing the zoning in the watershed from single-family residences to multifamily will bring more people and potentially more impacts to the lake and its watershed.
  • Rights-of-Way in the watershed are allowed without consideration of their potential impacts on the lake.
  • The risk of wildfires in the watershed continues to increase due to more people visiting the lake and taking advantage of the parklands in its watershed. Fire became a reality at the end of summer last year when 45 acres burned near Blue Canyon Road in the watershed.
  • The impact of 223,000 more visitors to the watershed just last year to enjoy the low-impact parklands resulted in significant increases in littering, pet waste, new trail construction, impacts to wildlife, and the increased risk of wildfires were some of the concerns listed.
  • Proactive planning and action is needed to address the impacts of climate change that will cause the increased frequency and magnitude of storms, and their ability to increase the intensity of silt and phosphorus loading to the lake.

A New Phase?

We may be entering a new phase in protecting Lake Whatcom and transitioning to restoring the lake to predevelopment standards. Several minutes during the JCC meeting were spent with staff and elected officials congratulating each other on the slowing and possibly halting the decline in the lake’s water quality.

The true story is that it was a group of dedicated citizens that worked very hard in the 1990s to meet with and convince elected officials including the County Executive, Bellingham’s Mayor, City of Bellingham and County Council members, City and County Public Works staff, and the public that immediate action was needed. The future of our community’s drinking water source was at risk of being irreversibly destroyed by inaction.

We talked to scientists to become educated on the problems, we met with staff at the Washington Department of Ecology and Department of Natural Resources on what was being done at the state level to protect the lake. We attended council meetings, handed out pamphlets and flyers at public events, and wrote articles in local newspapers.

As more of the public were educated on the consequences to our community if we failed to protect and restore our drinking water source, their voices joined ours to eventually convince the City of Bellingham, Whatcom County, and Lake Whatcom Water and Sewer District to take action.

We are at this phase of protecting and possibly reversing the decline in the water quality of Lake Whatcom due to the ongoing efforts of you and me. Elected officials only direct their efforts, funding, and staff to projects that have the greatest public support. We would NEVER have seen even this level of progress in stopping the decline in Lake Whatcom’s water quality had it not been for the efforts of so many of you in our community.

In answer to Councilmember Lilliquist’s question, yes we are slowly making progress; however, we need to continue being diligent in our efforts. Our community’s future depends on actively protecting, restoring, and preserving Lake Whatcom as our source of drinking water and never again taking this precious resource for granted.


April Markiewicz is an environmental toxicologist and recently retired as the associate director at the Institute of Environmental Toxicology at the College of the Environment at Western Washington University. She is also the president of the People for Lake Whatcom Coalition.


  • LWICT (Lake Whatcom Interjurisdictional Coordinating Team). 2023 Lake Whatcom Management Program Progress Report. Accessed 03/27/2024 at: lwmp_2023_progress_report.pdf – Google Drive
  • Strecker, A., Pickens, J., Archambault, C., Queen, K., Mitchell, R., Matthews, R., Matthews, G. 2024. Lake Whatcom Monitoring Project 2022/2023 Report. Western Washington University, Bellingham, WA 98225. February 16, 2024. Accessed 03/22/2024 at
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