Watertown is accurately named due to the body of water that creates a border running along our town from Boston to Waltham. The Charles River technically starts in Hopkinton and runs to the Boston harbor where it then deposits into the Atlantic ocean. The Charles has a reputation for being a city river, people assume it is dirty and not well taken care of. While that might have been the case in the 1980s when citizens and companies polluted directly into the river, it is now clean enough to swim in (in certain areas). In the past 30 years, there has been a large effort to make the river a clean and enjoyable element of Boston and surrounding towns. Every year the river gets a letter grade, it used to be around a D average but recently it receives a solid B.
Only one side of Watertown borders the river and my house is three houses up from the river. When I go to bed at night I can see the river from my pillow (fun fact: I can see people, bikes, cars, boats, trains, and planes from my room) I have also always had dogs which means at least two walks a day along the river for as long as I can remember. I have seen it through every season, time of day and weather. I personally have seen the river look very pretty, I always try to defend it. There is a path that runs along the edge of the river with trees on one side and the river on the other. There are many small species that are a constant presence, such as squirrels, chipmunks, birds, and many types of bugs. My mom is a biologist and for as long as I can remember she has pointed out the patterns of species and their characteristics.
I like Centennial woods a lot because it reminds me of the Charles river path at times. I live directly next to the city so there are a lot more paved surfaces and fewer trees. The river path definitely is not as thickly settled with trees but it is a nice piece of nature next to the city. The bottom of the river in Centennial woods is definitely nicer than the Charles River. The Charles River has a history of pollutants being in it and while the water is clean enough to swim in, the bottom has so many chemicals deeply layered that it is better left untouched and hopefully buried more. The area surrounding the Charles River has more pollution due to it being in a very urban area. There are often beer cans, plastic bags, paper scraps and other things that fall out of garbage trucks or people being sloppy. The land that Centennial woods sits on has many more hills and valleys than the Charles River which is essentially flat, Massachusetts does not have a very mountainous landscape. The Charles River water levels are controlled by dams, which are controlled by humans. The amount of rain can greatly affect both the Centennial woods river and the Charles River but the Charles is tightly managed by humans.