Colony Road Tree Filters, East Lyme


Eastern Redbud in bloom in a tree filter at the corner of Colony Road and Mayfield Terrace.


In 2012, the Eastern Connecticut Conservation District (ECCD)  partnered with the Town of East Lyme and CT DEEP to conduct a stormwater improvement project in the Latimer Brook watershed.  ECCD received funding from CT  DEEP through the Clean Water Act §319 NPS program to install five tree filters along Colony Road to treat stormwater runoff prior to its discharge through the existing storm drain system into Latimer Brook.

Tree filters work in tandem with existing storm drain systems to filter pollutants out of stormwater runoff before it is discharged into nearby waterbodies. NRWC and ECCD worked with the East Lyme public works department to identify the best locations for tree filters in the Colony Road neighborhood in order to improve water quality and protect Latimer Brook.

Latimer Brook has been listed by  CT DEEP as impaired for recreation  due to the presence of bacteria. Additionally, the Niantic River is listed as impaired for aquatic life support in part due to excess nutrients. Nutrients, including nitrogen and phosphorus, can be derived from natural sources such as decaying terrestrial and aquatic plants; chemical fertilizers; manure and pet waste; and malfunctioning or under-performing septic systems.  Latimer Brook is the largest tributary to the Niantic River, and hence the largest potential contributor of nutrients.

Since the tree filters were installed, bacteria levels in the stream have decreased significantly, and the stream has been de-listed.


Kwanzaa cherries in bloom in tree filters at the corner of Colony Road and Alscott Drive.


For more about tree filters, you can visit these sites:

            * LID Urban Design Tools

            * Tree Box Demonstration Project 

            * Stormwater Tree Pits