In 2015, New Jersey employed a statewide statistical survey that would enable the use of a randomly selected portion of NJ lakes to extrapolate the overall conditions of lakes in NJ. This data is collected to evaluate the trophic state of selected lakes and assess the ecological health of the State's lentic water resources. Lakes are monitored to develop baseline, status and trend information for New Jersey lakes.

For the Statewide Statistical Survey, 50 lakes, referred to as a Panel, are sampled over 5 years or 10 lakes per year. Lakes are selected using Generalized Random Tessellation Stratified survey design. The purpose of this design is to enable a statistically valid estimate of water quality condition for a statewide estimate. Potential sites included all lakes (public and private) that are greater than or equal to 5 acres, minimum one meter deep, including potable water supply reservoirs and unnamed lakes.

To achieve a comprehensive dataset, the survey lakes are sampled 4 times per year for 1 year from March through November. In addition to providing a statewide statistical estimate of NJ lake conditions, it will allow for the assessment of each individual lake sampled for use in the integrated  water quality assessment required under Sections 303(d) and 305(b) of the federal Clean Water Act. Each year, a new set of 10 lakes will be monitored. After 5 years, 50 lakes will provide data for a statewide assessment of lakes. Lakes are monitored at several in-lake monitoring stations for a variety of physical and chemical parameters, as listed below.

• Field parameters are analyzed immediately on-site and include dissolved oxygen, temperature, pH, conductivity, chlorophyll a, phycocyanin and turbidity


• General and nutrient laboratory parameters (e.g. Alkalinity, Phosphorus, Chlorophyll a)


• Secchi depth, habitat assessment, bathymetry mapping (where feasible)


• Harmful algal bloom screening


• A full list of sampled parameters can be found below

In 2014, DEP employed a rotating regional approach to integrated water quality assessment required under Sections 303(d) and 305(b) of the federal Clean Water Act. Through this approach, the Bureau of Environmental Analysis, Restoration and Standards produces a robust assessment of environmental conditions affecting water quality in each water region. This Regional Comprehensive Assessment incorporates one of five water regions (Atlantic Coastal, Lower Delaware, Northwest, Raritan and Northeast) during each Integrated Report cycle. The rotating basin approach results in a comprehensive assessment of the entire state every 10 years. This approach encourages development of measures to restore, maintain and enhance water quality uses that maximize effectiveness and efficiency in achieving positive environmental outcomes that are tailored to the unique circumstances of each region. The Lake Regional Monitoring Network was established in 2015 to support this approach.

During each monitoring cycle (1-2 years), a minimum of 10 lakes are monitored in the water region prioritized by the Bureau of Environmental Analysis, Restoration and Standards. Sites targeted for monitoring are selected based on a list of prioritization criteria (e.g. ownership, historical monitoring data, land use variables). A greater emphasis is placed on waterbodies in areas that currently have no water quality data or ones that are lacking enough data to make assessment decisions.

Beginning in 2022, monitoring will be conducted in the Raritan Water Region for a period of 2 years.

Click the buttons below for the current list of targeted lakes, Quality Assurance Project Plan, monitoring Parameters list and Lake mapper to view lakes on a map.

To achieve a comprehensive dataset, the targeted lakes are sampled 4 times per year for 2 years from March through November. This sampling allows for characterization of each lake and contributes to the integrated water quality assessment required under Sections 303(d) and 305(b) of the federal Clean Water Act. Sampling regions are then rotated resulting in a complete assessment of the entire State every 10 years. Lakes are monitored at several in-lake monitoring stations for a variety of physical and chemical parameters, as listed below.

• Field parameters are analyzed immediately on-site and include dissolved oxygen, temperature, pH, conductivity, chlorophyll a, phycocyanin and turbidity


• General and nutrient laboratory parameters (e.g. Alkalinity, Phosphorus, Chlorophyll a)


• Secchi depth, habitat assessment, bathymetry mapping (where feasible)


• Harmful algal bloom screening

Reference lake data documents baseline information on minimally-impacted lake water quality, ecological integrity, and the trophic state
of lakes within each ecoregion. Reference lakes are monitored every year and can be used to measure variations and trends resulting from climate change and land use. Data is also compared to disturbed lakes within the same ecoregion to gauge the degree of impairment. Reference data also serves to inform criteria development, specifically nutrients, to determine criteria that are attainable, appropriate for the ecoregion and adequate to control nutrient enrichment.

In 2015, 8 lakes were selected for the Reference Lake network using the criteria above. These lakes have been monitored at varying frequencies each year through 2019. In 2020, no sampling was performed. In 2021, these lakes were sampled once between July and August. A minimum of one monitoring event during this timeframe will be performed annually.

Lakes were selected with the intention of representing all five Omernik Level III Ecoregions within the State, except for the Northern Piedmont (no lakes fit the criteria below). These lakes are intended to be minimally disturbed by human activity and preferably in an area protected from human-induced changes.

Beginning in 2021, monitoring for this network is conducted once during the growing season between July and August. The lakes are monitored at multiple in-lake monitoring stations for a variety of physical and chemical parameters, as listed below.

• Field parameters are analyzed immediately on-site and include dissolved oxygen, temperature, pH, conductivity, chlorophyll a, phycocyanin and turbidity


• General and nutrient laboratory parameters (e.g. Alkalinity, Phosphorus, Chlorophyll a)


• Secchi depth, habitat assessment, bathymetry mapping (where feasible)


• Harmful algal bloom screening