Survey of the Nation’s Lakes

Fact Sheet

Purpose

Report on the 

condition of the 

Nation’s lakes, 

ponds, and 

reservoirs.

Help build state 

capacity for 

monitoring and 

assessment.

Promote 

collaboration 

across 

jurisdictional 

boundaries in 

the assessment 

of water quality.

What is the Survey of the Nation’s Lakes?

The Survey of the Nation’s Lakes is a statistical survey of the condition of our Nation’s lakes, 

ponds, and reservoirs. The Lakes Survey is designed to:

• Determine regional and national ecological integrity, trophic status, and recreational 

value of lakes.

• Promote collaboration across jurisdictional boundaries.

• Build state and tribal capacity for monitoring and analyses.

• Achieve a robust, statistically-valid set of lake data for better management.

• Develop baseline information to evaluate progress.

This is one of a series of water surveys being conducted by states, tribes, the U.S. Environmental Protection Agency, and other partners. In addition to lakes, partners will also study 

coastal waters, wadeable streams, rivers, and wetlands in a revolving sequence. The purpose of these surveys is to generate statistically-valid and environmentally relevant reports 

on the condition of the Nation’s water resources.

What is the goal of the Lakes Survey?

The goal of the Lakes Survey is to address two key questions about the quality of the Nation’s lakes, ponds, and reservoirs:

• What percent of the Nation’s lakes are in good, fair, and poor condition for key 

indicators of trophic state, ecological health, and recreation?

• What is the relative importance of key stressors such as nutrients and pathogens?

The sampling design for this survey is a probability-based network which will provide statistically-valid estimates of the condition of all lakes with known confidence. It is designed using 

modern survey techniques. Sample sites are selected at random to represent the condition 

of all lakes across each region.

What lakes are included in 

the Lakes Survey?

A total of 909 lakes are included in the Lakes 

Survey. The sample set is comprised of natural 

and man-made freshwater lakes, ponds, and reservoirs greater than 10 acres and at least one 

meter in depth located in the conterminous United 

States. The survey does not include the Great 

Lakes, the Great Salt Lake, natural saline systems, or treatment and disposal ponds. In order 

to examine potential trends in water quality, a 

representative subset of lakes from EPA’s 1972 

National Eutrophication Survey (NES) is included.

Lakes were selected to represent five size class categories as well as to provide relatively even spatial 

distribution across the lower 48 states.

Distribution of lakes in the Lakes Survey
What parameters will be measured?

The parameters measured in the Lakes Survey will be used to evaluate the ecological condition, trophic state, and 

recreational potential of lakes. The sampling will occur using consistent procedures at all sites to ensure that the 

results can be compared across the country. 

Key indicators to be measured include:

Trophic Indicators

• In situ temperature and dissolved oxygen profiles

• Water chemical quality and nutrient concentrations

• Chlorophyll a, Secchi disk depth, turbidity, and color

Ecological Integrity Indicators

• Sediment diatoms

• Phytoplankton

• Zooplankton

• Shoreline physical habitat conditions

• Macroinvertebrates

Recreational Indicators

• Pathogen indicator (enterococci)

• Algal toxin (microcystins)

• Sediment mercury

What is the schedule for the Lakes Survey?

The time line below lists the major phases of the Lakes Survey and the year they will be accomplished.

Activities

2006 2007 2008 2009 2010

Design Field Lab/Data Report Research

Target population

Indicators

Field/lab practices

Quality assurance plan

Training

Site reconnaissance

Sample collection

Field quality assurance

Lab analysis

Lab quality assurance

Data entry

Data quality assurance

Data analysis

Presentations

Peer review

Final report

Scientific issues

Policy issues

Supplemental data analysis

Methods refinement

For more information visit: www.epa.gov/owow/lakes/lakessurvey/ 

or email us at lakessurvey@epa.gov

Monitoring Branch (4503T)

U.S. Environmental Protection Agency 

1200 Pennsylvania Ave. NW

Washington, DC 20460

EPA 841-F-06-006

November 2006