Paradise Pond? More Like Disruptive Pond

Paradise Pond has been an iconic part of the Smith College campus since its purchase in 1871. In 1931, we saw the addition of an island to the center of the pond shortly followed by a diversion of the Mill River to enlarge the pond in 1939, requiring the addition of a dam. Its function and changes made to it have been mostly aesthetic. The man-made dam alters sediment flow downstream, resulting in buildups that require removal once every 8 years. Generally, dams are bad for ecosystems no matter the circumstances. They alter the natural flow of rivers, disrupt habitats, and cause changes in water quality.

Dams disrupt ecosystem balance via the change in turbidity from up and downstream of the dam. With the resulting sediment buildup, turbidity downstream of the dam increases, leading to a decrease in light filtration to aquatic plants and subsequently dissolved oxygen concentration. The decrease in both light filtration and dissolved oxygen drastically impacts the organisms residing in the area, largely limiting their growth. The Mill River dam particularly inhibits the filter-feeder macroinvertebrate population downstream of the dam and increases the scraper-feeder population. The ecosystems of the two locations are unnaturally altered by the presence of the dam. Sediment buildup also disrupts the natural habitats of the river's inhabitants by causing changes in erosion patterns, oftentimes harming plants along the banks of the river.

Smith has been responsible for dredging the sediment, a costly, time-consuming, and disruptive process. In the past, the method of dredging available was dry dredging, where the whole pond is drained to remove the sediment which is extremely disruptive to the local aquatic organisms, particularly to the macroinvertebrate larvae. To try to manage the disruptive nature of dry dredging, in 2008, Smith utilized a process called hydraulic dredging which removes sediment without water removal. The hydraulic dredging proved to be ineffective and disruptive. Additionally, the Northampton Dump closed, meaning that the cost of transportation of the sediment had been raised. Overall, it was an expensive bill for minimal results.

The buildup of sediment in Paradise Pond is inevitable. Regardless of technique, due to the presence of the dam, the sediment has to be removed periodically, meaning repetitive high-volume spending. Add to that the negative effects the dam has on the local ecosystem, removal of the dam would be more sustainable in the long run both economically and environmentally. If possible, I encourage you to contact local representatives to propose the removal of Paradise Pond shortly to restore the Mill River habitat. Let them know of your concern for the health of our environment as well as the cost benefits of removing the dam.

References:

Parks and Landscape Features. (1990). Form H. Massachusetts Historical Commission.

Pratt Lab. (2020, September 14). Managing Sediment in Paradise Pond and Mill River [Video]. Youtube.