Water. About three feet of it falls as rain and snow in this part of New England every year. In cities and other developed areas, much of it runs off rapidly, down into catch basins and storm drains, where it races through pipes and discharges into our rivers. In forested areas, it's a different story.
Over half the precipitation that falls in a forest eventually returns to the air through evaporation or transpiration by plants. The remainder percolates into the soil or flows across the surface of the landscape until it enters a stream.
Just where this rainwater flows depends on topography. With its hills and valleys, the earth is divided into watersheds or river basins, each one isolated from the next.

If you pour water in a bucket on one side of the Westfield watershed divide, it will flow west into the Housatonic River Watershed, eventually weaving its way through the Berkshire towns of Western MA, through western Connecticut and ultimately into Long Island Sound in CT's southwestern corner. However, if you pour the water on the other side, the water will flow east into the watershed of the Westfield River, one of the large tributaries of the CT River. Its route to the sea will be about the same distance, but its pathway will be quite different.

When rain falls in an area like this, individual raindrops coalesce, trickling down twigs and bark to the ground. On the ground these tiny rivulets merge with others, which collect in small streams, which join other streams, much like the branches of a tree. Ultimately a great river forms.

In the upper reaches of a forested watershed, stream temperatures are low, averaging about 50 F year round. This relatively cool temperature is due to the large amount of groundwater seeping out of the banks. But it's also cool because it's typically shaded by a canopy of overstory branches.

As the turbulent water tumbles and leaps past large cobbles and mossy boulders, it mixes with atmospheric oxygen. Since oxygen dissolves more easily in cold water, these waters become highly oxygenated. In a stream like this one you can nearly always find brook trout and the creatures trout like to feed on--the larval stages of stoneflies, mayflies and caddisflies.

Stoneflies and mayflies have evolved flattened, streamlined bodies and specialized behaviors that enable them to avoid being flushed downstream by the rushing water. Curiously, due to the physics of flowing water, there is a thin zone that covers the surface of the bottom rocks where the speed of the water drops to zero. This phenomenon enables these flat insects to crawl around and forage, in spite of the swift currents just above them.

Other creatures have evolved different adaptations to keep from washing downstream. Some burrow, other live below rocks; black fly larvae weave silken mats of saliva which they attach to with a structure resembling a grappling hook. Some caddisflies form cases of sand grains that act like lead sinkers and protect them from predators.

Fast, cold and shaded. It's a combination that limits the growth of microscopic plankton, the tiny plants that are the base for most aquatic food chains. Instead of plankton, in this habitat the nutrients come from dead plant material. Leaves, twigs, and bits of bark. This is food for bacteria, fungi, insect larvae and grazing snails. As the organic material is broken into smaller components, other organisms filter it out using brush-like structures or build nets of saliva to collect the decomposing fragments.

As the leaves and branches, silt and sediments flow downstream, their journey is often obstructed by fallen trees and rocks. Pools are created, beaches deposited and in stretches where the river flows straight, riffles form. Each is a distinct habitat and each supports a different suite of aquatic creatures.

As the river flows downstream, we can see a number of changes. The gradient is less steep and the current is slower. Large, mossy boulders are replaced by streambeds composed of cobbles, gravel and sand. Here in the mid-reaches, the river widens and is no longer shaded by bordering trees. This shallow-bedded stretch tends to warm up during the day, with a slight drop in temperature at night. It's here that we see the greatest daily and yearly temperature fluctuations within the entire river system.

With a slower current, more sunlight and warmer temperatures, there is a big increase in the growth of algae, which in turn supports lots of microscopic one-celled organisms known as zooplankton. The base of the food chain is broadened, with a corresponding increase in the diversity of plants, snails, insects and fish.

Just before it reaches the Connecticut River, our waterway becomes a deep, silt-bottomed river. There is more water here, which makes it less vulnerable to daily fluctuations in temperature. The stretch is much warmer, in part because the water contains lots of silt, tiny bits of organic material and nutrients like nitrogen and phosphorus from agricultural runoff and sewage treatment plants. The caddisflies, stoneflies and trout we saw in the upper reaches are gone, replaced by creatures that can tolerate low oxygen levels and warmer temperatures, like carp, catfish, bluegill, midges, and aquatic worms.

In less than thirty miles, the runoff has dropped 2000 feet, passed from rugged, forested slopes, through some very wild and scenic country, offering some of the best cold water trout fishing and kayaking in the state. Here at the mouth, we find a remarkable contrast to those upper reaches. The plants have changed, the fish have changed, the entire dynamics of the river are different. The Westfield River Watershed drains over 500 square miles but comprises less than 4% of the CT River's total watershed. That means there are lots and lots of incredible places yet to visit.

Questions and Activities after Watching the Video:

1. What watershed is your school in? How many square miles does it encompass? Using U.S.G.S. topographic maps, identify all the brooks and rivers in your town. How many miles of tributary streams are in your community? What are the surrounding watersheds?

2. Using a topo map (and other maps) and your knowledge of local streams (and maybe catch basins), try to trace the route of the rainwater that falls on your school all the way to the ocean.

3. Collect some data over a period of time at a site on a stream near your school (or home). Keep it simple. Collect data on temperature, turbidity, flow rate, insects or other macroinvertebrates. Keep a record of your data with dates, # of observers, techniques used, unusual sightings, etc.

4. Go fishing at your favorite fishing hole. Take photos or draw all the species you catch over an extended period of time. Label these with the common and scientific names. Learn some things about these fish. Were they introduced to North America or are they native? When do they spawn? What’s their natural range?

5. Make a collection of aquatic and wetland plants from a nearby river or wetland. Use a simple plant press to preserve them. Can you note any special adaptations for living in saturated or inundated conditions?

6. Make a collection of freshwater mussels or snail shells from a nearby stream, river or pond. Try to identify them using the Vermont Guide To Freshwater Mussels, available from the Vermont Chapter of The Nature Conservancy, 27 State Street, Montpelier, VT 05602. Tel: 802-229-4425.

7. Prepare a brochure/rap song/skit/story/journal on a special natural place near your home or within your water community’s watershed.

WebSites: http://www.riverwatch.org http://epa.gov/owow/ http://nwf.org/nwf Resources for Teachers: Grades 6-12: Wicked Big Puddles. Produced by Reading High School, Reading, MA. (H) A multidisciplinary curriculum to vernal pools. Grades 9-12. Water Wisdom. Produced by the MWRA. Telephone 617-242-7110 (H) A great guide for teaching about water cycles, water and society, water purity, volumes, economics of water use, domestic water conservation, and how to perform a school audit. An appendix of resources is also included. Connecticut River Watershed Council. 1995. The River That Connects Us. CRWC, 1 Ferry Street, Easthampton, MA. 413-529-9500 (H) A watershed overview. Jorgensen, Neil. 1977. A Guide to New England’s Landscape Chester, CT: Globe Pequot. River Watch Network. 1993. A Simple Picture Key: Major Groups of Benthic Macroinvertebrates Commonly Found in Freshwater New England Streams. Montpelier, VT Contact: 802-223-3840

This web page made possible in part by a grant from the Massachusetts Department of Environmental Management Greenways and Trails Demonstration Grant Program & the Silvio O. Conte National Fish and Wildlife Refuge Challenge Cost Share Program, 1997.