Water Quality

Big Rock, Watchic Lake

Big Rock, Watchic Lake

By most any measures, the quality of Watchic Lake is very good. A clean lake benefits everyone. Not only does it create excellent recreational opportunities, it also ensures a healthy environment for wildlife, and helps maintain shoreline property values.

One way to measure water quality is to use a Secchi Disk, which is an instrument that measures clarity. It is lowered into the water and the depth at which the disk can no longer be seen is recorded as a measurement of lake clarity. Secchi Disk readings are taken regularly at Watchic Lake and are in the 4 to 4.5 meter range (meaning transparency down to about  15 – 16 feet). For real-time Secchi disk readings during the summer, touch or click here for Maine VLMP Near Real Time Lake Data.

The Watchic Lake Association (WLA) is dedicated to monitoring and improving the quality of Watchic Lake. The Association does regular lake quality readings,  manages the dam to ensure appropriate water levels, directs major remediation projects (such as the Paine Neighborhood project), coordinates the LakeSmart program, and works with property owners on an ad hoc basis to address quality issues.

It is up to all of us to protect this lake. While we own the property currently, we are but stewards for now; the future of the lake is in our hands.

  • Please consult Standish Town Hall and/or the Department of Environmental Protection for information on any changes to your property.
  • Expansion, tree removal, and drainage changes can adversely affect water quality and are all closely monitored.
  • Landscaping products that were acceptable in an urban environment may create problems in a shore front location. Phosphorous from runoff is our worst enemy.

2022 Water Quality Fall Update

By Cathy Watson

Staring out at the Lake just before Christmas reminds me that similar to other lakes in Maine, Watchic Lake continues to experience longer ice-free periods (average >270 days over last 3 years). These warmer temperatures in the Spring and Winter are an environment that could disturb the delicate ecological balance of the lake.  This is one reason the Watchic Lake Water Quality Committee continues to diligently monitor our lake each season.  A full set of automatic loggers were deployed from the buoy (at the deep spot in the lake) on May 12, 2022. The loggers take temperature and dissolved oxygen levels every 15 minutes.  The loggers were converted to the winter configuration (temperature only) on October 21. In addition, we took Secchi disk readings (for water clarity; Figure 1) and manual readings of temperature and dissolved oxygen (Figures 2 &3) at about 2-week intervals, and water samples for chemical analysis every month.  The initial data suggests everything is similar to last years’ data, but stay tuned for the full report next February.

2021 Full Year Water Quality Report

Based on the findings contained in the 2021 Watchic Lake Water Quality Report, the water quality of Watchic Lake remains good, and is substantially unchanged from data collected over the previous 5 years (2016-2020), and from data back to the 1970’s. Specifically, water clarity and total phosphorus levels are consistent with previous years and consistent with other Maine lakes like ours. All data reported here was collected by the Watchic Lake Water Quality committee and represents over 70 hours of volunteer time with a budget of ~$1500 for lab work and testing equipment (3-5 year life).

2020/21 winter resulted in a short period when the lake was frozen (86 days) and had a long ice-free/algae growing period (268 days). In 2021, we experienced a very dry June (0.6 inches of rain) and very wet July (8.7 inches). Despite these extremes, lake quality as measured by trophic state indicators (water clarity and core total phosphorus and chlorophyl-A levels) was similar to recent years. Consistent to previous years, we experience long periods of low dissolved oxygen levels at the bottom of the lake in 2021. At the 11m depth, the dissolved oxygen was below 1mg/L from May-Oct and at 11.5m Total Phosphorus was elevated (averaged 32mg/L). Such conditions can restrict fish populations and increase algae growth.

The Watchic Lake Association (WLA) applied for and received a state grant to address water quality issues in Watchic Lake. With this grant, the WLA is currently working with the DEP, the city of Standish, and homeowners to help reduce nutrient laden run-off from storms (especially megastorms) washing into the watershed and lake. These run-offs cause negative changes in the lake’s water quality. Without these continued efforts, significant algae blooms could occur. In addition, while to-date no invasive plant or aquatic species have been identified in Watchic Lake, the WLA continues to monitor the lake for signs of these.

Use the Contact Us page should you have questions.

2021 Fall Water Quality Report

The warm spring brought another early ice-out date (27-Mar-21).  However, the relatively dry Spring followed by the rainy summer resulted in water clarity similar to what has been observed in recent years (see Figure 1).

Lake temperature rose quickly to a peak around July 1st.  With the intermittent rain through the summer, the lake didn’t continue to warm, but stayed at a great swimming temperature through late August.  As temperatures dropped at night through September the lake cooled quickly.  As you can see from the latest data (1-Oct-21), the lake is now getting close to fall turnover (when the whole lake is the same temperature), and the end of our monitoring season.

As in recent years, Dissolved Oxygen remains okay through the epilimnion (or top, active part of the lake) to a depth of about 5m, but then drops quickly to below 5 mg/L (concentration needed for fish viability) by 7m (see Figure 3).

Earlier Water Quality Reports