Small dams are common in streams and rivers, but they can have a large impact on wildlife.

Small dams slow the flow of water in Milton’s own Pine Tree Brook, simultaneously increasing temperature and diminishing dissolved oxygen, which can have a major impact on the stream’s wildlife. Many aquatic life require on consistent qualities in a habitat to thrive. However, the implementation of dams, tributaries, storm drains, and other human-made infrastructure changes those necessary factors.

We aimed to test if the temperature of Pine Tree Brook is affected by the presence of a dam or an obstruction by comparing each site to the Headwater Spring on William Greggs property. Of the two locations with successfully collected data, the Earthen dam, which is the site categorized by a very large pool and more interference of human infrastructure, not only had warmer temperatures than the Bridge site over the 32 day period they were deployed, but also became warmer earlier than the water at the bridge.

The graph depicting the average daily temperature of the spring, bridge, and earthen dam locations shows the bridge and the spring as having similar temperature records. The line representing the earthen dam does not seem too far off, however when the graphs are broken down into daily maximum and daily minimum temperature graphs, the difference in the earthen dam's data is much more noticable. On the graph depicting the comparison of the daily maximum temperatures of the spring, bridge, and earthen dam site, the blue line, which represents the data collected at the spring, is the baseline temperature the data from the other sites is being analyzed against. The changes in the yellow line, which represents the temperature of the earthen dam, are more erratic and drastic than the temperature changes of the bridge site. This is largely due to the amount of human infrastructure in the area. The earthen dam site is located by the side of the road in broad daylight with no coverage from trees, leaving the reservoir open to the sun. The bridge site however, is located directly in the section of Pine Tree Brook categorized as a small meandering stream. From the spring to our first sensor, downstream of the stone bridge, besides the bridge, there was no other unnatural obstacles which the stream had to pass through. The red line, or the data from the bridge site, is less severe in its temperature changes and overall lies closer to the data recorded from the spring. The graph that depicts the daily minimum temperatures of the three sites also shows similar results. The earthen dam proves to be more susceptible to temperature changes than the less urbanized bridge location and remains further from the baseline than the bridge as well.

Though we don't have mathematical uncertainty in our data, our experiment leaves many unanswered questions and potential improvements. We collected only half the data than we originally planned, which led to much speculation in our analysis. Moving forward, collecting data from all original sites would improve the experiment. More sensors could have been placed further downstream, with the potential to consider sea level rise with accordance to interactions between Pine Tree Brook, the Neponset River, and Boston Harbor. Sensors could remain in Pine Tree Brook for a longer period of time than 30 days. Sensors could also be placed both upstream and downstream of the chosen dam sites to analyze changes in temperature specific to the immediate area of each dam.