Water Quality

History
Understanding the present challenges of managing Culver Lake water requires knowing the history of the lake. The lake is one of the largest naturally formed lakes in NJ. It was formed by the receding glacier. The lake has a water shed of several square miles. Ground water, surface water from the water shed plus direct precipitation result in a surplus of water that flows downstream to the Paulinskil River and on to the Delaware River.
In the late 19th century, railroad transportation brought tourists to the lake and led to the building of several seasonal hotels. The pristine water of the lake continued even as development added seasonal shoreline homes in the early 20th century. But as demographics continued to change with the addition of year round homes, the lake’s water quality began to degrade in the 1980’s as algae blooms and weed growth intensified.
The Normanoch Association, alerted to the worsening eutrophication problem, contracted a lake and watershed study in 1989. This study summarized the problems and corrective measures that were needed to reverse and hopefully restore lake water quality.

The Problem
The Culver lake water quality study found the following conditions:

  1. Excessive weed growth
  2. Hypolimnetic anoxia
  3. Impaired transparency
  4. Sediment accumulation
  5. Loss of trout habitat

The major causes of Culver Lake water quality problems:

  1. Septic systems
  2. Internal recirculation of nutrients
  3. Alewife population dynamics
  4. Generation of organic sediments

Major Elements of Restoration Plan

  1. Correct anoxic conditions and internal phosphorus recirculation load through aeration.
  2. Implement a Septic Management Plan
  3. Rotovate the Stehr Tract and intensify harvesting in the Causeway Cove
  4. Decrease the alwife population and increase predatory fish.
  5. Develop and implement a land-use plan (Carrying capacity)
  6. Intensify erosion control Continue monitoring water quality

In-lake Restoration
The Normanoch installed several aeration devices designed to limit the anoxic condition of the hypolimnium (hypolimnetic aeration) and provide an oxygenated layer at mid depth (layer aeration) to reduce the recirculation of phosphorus. The lake stratifies in the summer months. Although photosynthesis mechanisms provide abundant level of oxygen at the surface layer, the lowest depth of the lake >40ft. show early signs of becoming anoxic despite the hypolimnetic aeration. The decay of organisms and the resultant biological oxygen demand exceed the aerators capacity. Nutrients that reside in the lakebed are released under the anoxic condition that exists when it is devoid oxygen. The Normanoch is planning a nutrient inactivation program that will greatly lessen the amount of phosphorus recirculation. Volunteers monitor lake water on a weekly frequency from early spring to middle fall. Samples of water at depth are analyzed for inorganic nutrient levels and qualitative algae counts. Macrofyte (weed) growth and propagation.

Watershed
More recently this year and next, the Normanoch Association’s consultant will update the 1989 lake water quality study to reassess which areas of our lake management and restoration plan require additional attention.
Water Quality volunteers recent activities include shoreline monitoring for septic leachate for the first time in over 20 years. Using a conductivity meter, volunteers recorded conductivity readings every 50 feet as the shoreline was navigated. Numerous suspect inflows were identified, photo documented and will be followed up in accordance with the Normanoch Association’s Policy on Septic Problems. In 2013, the lake was drawn down to work on the dam. While the shoreline was exposed, volunteers sampled inflows and inspected and photo documented various drain pipes as well as intake pipes.
Further emphasis on watershed nutrient loading is anticipated as the Association continues to gather storm related data from key selected storm drain locations.