As of May 2024, Chebacco Lake continues to face significant challenges:

1. We continue to lose the long battle for a healthy lake. Excess plant growth from phosphorous overloading remains the chief problem.
   

2. Human impacts throughout the watershed are the cause.
   

3. The threat horizon is worsening every year. Climate change, invasive species, and development pressure are adding new stress to an already vulnerable system.

As with the human body, lakes have a set of vital signs that help indicate their overall health. These include water clarity, dissolved oxygen, nutrient levels, and phytoplankton — microscopic plants living in the water.

Water-quality sampling conducted in May and July 2023 revealed several warning signs.

Lake Living & Learning is intended to provide homeowners and lake lovers with a strong foundation for understanding the watershed, the ecology of its lakes and ponds, and the opportunities available to help preserve the health of the Chebacco Watershed.

This first installment focuses on three fundamental watershed concepts:

1. Watershed: Life Follows Water's Flow

2. Lakes and Ponds Are a Watershed's Hotspots

3. The Water Cycle Is the Heart of a Watershed Ecosystem

A watershed, also known as a drainage basin or catchment area, is the land area that drains water, sediment, and dissolved materials to a common outlet such as a lake, river, or ocean.

It acts much like a funnel, collecting and channeling water toward a central point.

The Chebacco Watershed is the drainage basin encompassing Chebacco Lake, Beck Pond, Round Pond, Gravelly Pond, Coy Pond, and approximately one mile of Alewife Brook to the Apple Street bridge.

The Chebacco Watershed includes portions of five Massachusetts communities:

1. Essex: 1,890 acres

2. Hamilton: 1,613 acres

3. Manchester-by-the-Sea: 658 acres

4. Wenham: 329 acres

5. Beverly: 110 acres

Water flows naturally from Chebacco Lake through Alewife Brook for more than a mile to the Apple Street bridge, the downstream boundary of the Chebacco Watershed. There are no manmade dams or barriers along this stretch.

From there, water continues at a steeper gradient into the Essex River and the expansive estuary known as Essex Bay. In this sense, the Chebacco Watershed forms the upper reach of the larger Essex River Watershed, while Essex Bay forms the lower reach.

Essex Bay is a significant part of the Great Marsh, the largest continuous salt marsh in New England. It is also an important ecological and birding resource. Alewife, or river herring, travel up the river each spring to spawn before returning to the ocean.

Only a little more than 1.2 percent of all freshwater on Earth is surface water. Lakes and ponds are therefore especially important elements within watersheds, accumulating surface water and supporting vibrant biological communities.

At the same time, inland waters are closely linked to changes taking place on land and in the atmosphere through the transport and storage of water, nutrients, contaminants, and energy.

Part of the joy of living near Chebacco Lake and its tributary ponds is the constantly changing display of the natural world. The ecological abundance can change so rapidly that it sometimes feels as though the watershed experiences "52 seasons per year” instead of four.

Diverse biological communities and habitats create a critical land-water synergy that supports the resilience of the entire watershed ecosystem.

Chebacco Lake covers approximately 209 acres, but its average depth is only 9 feet.

The lake reaches a maximum depth of approximately 22 feet.

At the deepest locations, pockets of sediment are approximately 15 to 25 feet thick.

Precipitation and snowmelt are the initial water inputs within a watershed. Water then moves through the system by several pathways:

1. Surface runoff

2. Groundwater flow

3. Evaporation from surface water

4. Transpiration from trees and plants

5. Human withdrawal through wells

Fluctuations in precipitation influence lake levels, water quality, and ecosystem dynamics throughout the watershed.

Natural ecosystems throughout the Chebacco Watershed are remarkably adept at using the normal flows of energy, water, and nutrients moving through the system.

Birds arrive in spring as insects appear. Alewife swim upstream when water temperatures reach approximately 50 degrees. Meanwhile, microorganisms throughout the lakes and ponds continuously adjust their activity in response to sunlight, nutrients, and temperature.

The lake's water volume is flushed and replaced relatively rapidly from March through May.

During summer and early fall, however, the flushing rate drops dramatically. The reduced movement of water during this period can adversely affect water quality.

Natural systems become stressed when weather conditions move outside normal patterns — particularly during droughts and periods of heavy rainfall.

Significant drought occurred in 2016, 2017, 2020, and 2022. By contrast, 2023 was exceptionally wet, with 14 storms producing one inch or more of rainfall.