Census Program


Anyone who visits the Fresh Pond Reservation knows that it's a busy place. Every day, hundreds of people visit the Reservation to complete the loop around the pond, bike, wander throughout the paths and nooks, socialize, and much more. In 2010, Watershed Division staff members developed the Fresh Pond Reservation Census Program to better quantify the number of visitors and to determine the many different user types.

The Census Program incorporates a combination of staff and volunteer-collected user surveys and unattended Eco-Counter sensors to provide documentation on user group types, patterns, and numbers at the Reservation. These data help the Water Department to better manage the Reservation, develop and implement strategies to reduce user conflicts, and to focus restoration projects in popular locations throughout the Reservation.

Staff and volunteers conduct surveys of user type, group size, and travel direction periodically at Eco-Counter sensor locations. These surveys both supplement and check the data collected from the Eco-Counter boxes installed at the Reservation. Two of the boxes are located along the Perimeter Road, one at the water treatment plant (WTP) and the other near Little Fresh Pond (LFP), and the last is located at the entrance pathway at Black's Nook. The Eco-Counters tally both the number and direction of users by using a passive infrared sensor and a lens to detect small temperature changes caused by people passing the sensor. The sensors collect no other information. For quality control, data from the Eco-Counters is downloaded weekly and screened for anomalies.  Future sites for additional sensors include the golf course and Lusitania Meadow entrances, and the bike path.

 Eco-Counter at Fresh Pond Reservation.

Eco-Counter at the Water Purification Facility.


In both 2011 and 2012, the average daily count by the Eco-Counter sensors on the Perimeter Road was 1,100. Assuming that most people complete only one loop, that's an average of over 1,000 people visiting the Reservation a day.  An example of the daily count totals for all sensors is provided below.

EcoCounter Daily Results 8/4/13 - 8/11/13.

User type data collected from the surveys, shown in the pie chart below, indicates that almost half of all users at the Reservation are walkers.

Reservation User Type Pie Chart, 2011-2012

The data collected from the Eco-Counters is compared to the walkers, runners, and cyclists tallied in the surveys. Reservation users who are shorter than the height of the Eco-Counters, such as children and dogs, are not tallied by the Eco-Counter and thus not included in the error calculation. The running average error between the sensor counts and survey data is approximately 10%, the majority of which is attributed to differences caused by side-by-side groups the sensor detects as one count.  Comparisons between the surveys and sensor results imply that the sensors consistently underestimate total user amounts, indicating that the Eco-Counters provide conservative estimates of Reservation usership.



Fresh Pond Reservation Census Program Data Collection Summary, 2011-2012.

July 2013 Daily Average EcoCounter Counts.

For more information on the Eco-Counter boxes, click here to visit their website.