
Tatnuck Brook begins in Holden, as the outlet of Holden Reservoir Number Two. It travels into Worcester where it is the feeds Cook’s Pond, Patch Reservoir, Patch Pond, Coes Reservoir and Coes Pond. Click here for a detailed map of the watershed:
The information on this page is from the US Environmental Protection Agency web site https://www.epa.gov/hwp
What is a Watershed?
A watershed – the land area that drains to one stream, lake or river – affects the water quality in the water body that it surrounds. Like water bodies (e.g., lakes, rivers, and streams), individual watersheds share similarities but also differ in many ways. Every inch of the United States is part of a watershed – in other words, all land drains into a lake, river, stream or other water body and directly affects its quality. Because we all live on the land, we all live in a watershed — thus watershed condition is important to everyone.

Watersheds exist at different geographic scales, Tatnuck Brook Watershed is relatively small and is located in portions of Holden and Worcester, but is part of the Blackstone River Watershed, which begins here at Tatnuck Brook. The Blackstone River follows a southeast course from Worcester as it flows through Massachusetts into Rhode Island. Just north of Providence, the Blackstone River flows into the Seekonk River and then to Narragansett Bay.
What is a Healthy Watershed?
A healthy watershed is one in which natural land cover supports:
- dynamic hydrologic and geomorphologic processes within their natural range of variation,
- habitat of sufficient size and connectivity to support native aquatic and riparian species, and
- physical and chemical water quality conditions able to support healthy biological communities
Natural vegetative cover in the landscape, including the riparian zone, helps maintain the natural flow regime and fluctuations in water levels in lakes and wetlands. This, in turn, helps maintain natural geomorphic processes, such as sediment storage and deposition, that form the basis of aquatic habitats. Connectivity of aquatic and riparian habitats in the longitudinal, lateral, vertical, and temporal dimensions helps ensure the flow of chemical and physical materials and movement of biota, the animal and plant life of a region. A healthy watershed has the structure and function in place to support healthy aquatic ecosystems. Key components of a healthy watershed include:
- intact and functioning headwater streams, floodplains, riparian corridors and biotic communities;
- natural vegetation in the landscape; and
- hydrology, sediment transport, fluvial geomorphology, and disturbance regimes expected for its location.
Are Healthy Watersheds Very Common?
Unfortunately not. Healthy watersheds are uncommon, particularly in the eastern U.S. as well as in most other parts of the nation that are urbanized, farmed, or mined. Large tracts of protected wildlands, mostly in the western U.S., are where most healthy watersheds can be found. However, some healthy watersheds exist in many regions of the country where water pollution has been prevented or well controlled, and where communities maintain the benefits of their clean waterways. The Tatnuck Brook Watershed Association is working to improve the health of our watershed.
How Might Healthy Watersheds Affect Me?
You may potentially benefit from healthy watersheds in numerous ways, generally unseen and unrecognized by the average citizen:
- Healthy watersheds are necessary for virtually any high quality outdoor recreation sites involving the use of lakes, rivers, or streams. Great fishing opportunities are usually due to healthy watersheds that surround the waters that people love to fish.
- Your drinking water, if it comes from a surface water source, might be substantially less expensive to treat, if a healthy watershed around the water source filters pollution for free.
- Your property values may be higher, if you are fortunate enough to reside near healthy rather than impaired waters.
You and your community’s quality of life may be better in these and other ways due to healthy watersheds; now, imagine how unhealthy watersheds might affect you as well.
Why Do Watersheds Need to Be Protected?
Healthy watersheds not only affect water quality in a good way, but also provide greater benefits to the communities of people and wildlife that live there.
A watershed – the land area that drains to a stream, lake or river – affects the water quality in the water body that it surrounds. Healthy watersheds not only help protect water quality, but also provide greater benefits than degraded watersheds to the people and wildlife that live there. We all live in a watershed, and watershed condition is important to everyone and everything that uses and needs water.
Healthy watersheds provide critical services, such as clean drinking water, productive fisheries, and outdoor recreation, that support our economies, environment and quality of life. The health of clean waters is heavily influenced by the condition of their surrounding watersheds, mainly because pollutants can wash off from the land to the water and cause substantial harm.
Streams, lakes, rivers and other waters are interconnected with the landscape and all its activities through their watersheds. They are influenced by naturally varying lake levels, water movement to and from groundwater, and amount of stream flow. Other factors, such as forest fires, stormwater runoff patterns, and the location and amount of pollution sources, also influence the health of our waters.
These dynamics between the land and the water largely determine the health of our waterways and the types of aquatic life found in a particular area. Effective protection of aquatic ecosystems recognizes their connectivity with each other and with their surrounding watersheds. Unfortunately, human activities have greatly altered many waters and their watersheds. For example:
- Over the last 50 years, coastal and freshwater wetlands have declined; surface water and groundwater withdrawals have increased by 46%; and non-native fish have established themselves in many watersheds (Heinz Center, 2008).
- A national water quality survey of the nation’s rivers and streams showed that 55% of the nation’s flowing waters are in poor biological condition and 23% are in fair biological condition (U.S. EPA, 2013). Compared to a 2006 survey (U.S. EPA, 2006), which only assessed wadeable streams, 7% fewer stream miles were in good condition.
- Nearly 40% of fish in North American freshwater streams, rivers and lakes are found to be vulnerable, threatened or endangered; nearly twice as many as were included on the imperiled list from a similar survey conducted in 1989 (Jelks et al., 2008)
- Rainbow trout habitat loss from warmer water temperatures associated with climate change already has been observed in the southern Appalachians (Flebbe et al., 2006).