Watersheds | Water Quality

Water plays a significant role in the Catawba Valley.   It played a huge role in forming the valley and it continues to connect land and lives up and down the valley.  Paying attention to the rivers and streams in this valley is particularly important because it spans the headwaters region for two major river basins in the region — Catawba Creek which flows into the James River and ultimately the Chesapeake Bay; and the North Fork of the Roanoke River which joins the Roanoke River and flows into the Albemarle Sound.

Watersheds

A watershed is the area of land that drains into a particular body of water. Imagine a bathtub — when the shower is turned on, water comes down all over the inside the tub and anything else that is in the tub.  All of that water eventually runs towards a single drain.  What falls outside of the tub goes someplace else — or outside of the tub’s watershed. We know what defines the boundaries of that tub’s watershed — the highest points or the edge.

Watersheds on the ground are a little more complicated, but not much. When we look at the terrain of the area, we get a general idea of how water will flow. If you pour a cup of water on the ground at the north face of Catawba Mountain, it will eventually flow down into the valley.  What is particularly interesting in the Catawba Valley is that it’s situated East to West on overlapping watersheds. During a single rain storm, water falling in the Catawba Valley will flow into both the Roanoke River and the James River, depending on what end of the valley the raindrop hits the ground.

Headwaters Region

The map on the left provides a more detailed look at the valley;  it’s a little easier to see why this area is so important for water quality in the broader region.  The solid black line marks the boundaries for two sub-basins, which in reality are parts of two entirely separate watersheds.  The eastern side of the divide flows into the Upper James River and the southwestern side flows into the North Fork of the Roanoke River. Both of these watershed are situated on karst landscapes, which contribute to their water supply and flow.

Upper Roanoke River & Albemarle Sound

The Roanoke River watershed comprises roughly 9,580 square miles of Virginia and North Carolina, with over 400 miles of rivers and streams flowing into the Albemarle Sound.¹  The Ablemarle Sound is considered the country’s  second largest estuary system (meaning it maintains both freshwater and salt water ecosystems.²  The North Fork of the Roanoke River which flows through the Catawba Valley is specifically in the Upper Roanoke sub-basin, shown right.

Upper James River & Chesapeake Bay

The James River watershed covers about 10,000 square miles of Virginia — roughly a quarter of the state.³ While the mainstem of the river extend 340 miles from the West Virgina border to the Chesapeake Bay, there are hundreds of additional miles of small creeks and streams that feed into the river. Catawba Creek is a tributary in the Upper James River watershed.

The water flowing in Catawba Creek is major source of drinking water for the residents of the City of Roanoke and northern Roanoke County.   A tunnel located at the base of Tinker Mountain diverts a portion of the water from Catawba Creek into Carvins Cove Reservoir, which has a 6.4 billion gallon capacity.  Water filtration costs are reduced when clean water comes into the reservoir, so caring for our streams and land is also a long-run cost-saving strategy.  Read more about protecting the Carvins Cove watershed in a special edition newsletter produced by the Western Virginia Land Trust and Roanoke County.

Not sure what watershed you live in? Check EPA’s Surf Your Watershed page and find out.

Water Quality

Officially, there is not really a difference between a river, creek, and a stream, but most people would say that a river is larger. To make things simple here, we will refer to the main sections of Catawba Creek and the North Fork which run through the valley as creeks, and the smaller tributaries which feed into them as streams, all of which flows downstream into larger rivers. Any given section of a creek and stream is going to vary in terms of its shape, size, and the amount of water passing through it (its flow), depending on the terrain and the surrounding land cover. Creeks and streams flowing down steep rocky areas are going to look very different than those meandering slowly across flat grassy fields. One is not better or worse than the other — it just reflects the physical surroundings.  But there are two big ways that these creeks can be affected by how we manage the land they run through.  Though careful management of the land surrounding these creeks and streams, we can reduce the amount of erosion and pollution that affecting the quality of the water.

Erosion

Erosion is the process of breaking down and displacing rock and soil through the abrasive effects of water and wind. In a creek or stream, the flow of water erodes the sides or banks over time. Erosion is a naturally occurring process that isn’t necessarily good or bad — it happens as shown in the video below. The problem is that when we increase the surface area of pavement and asphalt that doesn’t allow water to absorb into the ground, the speed of water flowing off of that surface and into the creeks increases.   If we don’t have trees or shrubs to slow the water down before it enters the stream, or if their roots aren’t there to hold the streambanks in place, we loose lots of soil into the water.  And if that streambank has also been trampled by livestock, we speed up and intensify the erosion process even more.⁴

In 2007, a study was completed with high school and Virginia Tech students to measure streambank erosion on the North Fork of the Roanoke River and along Catawba Creek.  This study looked at erosion levels on individual parcels, and indicated that roughly 30% of all stream front properties along the valley has some degree of streambank erosion, though this estimate is thought to be low.  See the brochures produced containing the parcel maps and data for each creek below.

• Streambank Erosion Along Catawba Creek flier
• Streambank Erosion along the North Fork flier

Pollution

Just like how our actions on land can affect the rate of streambank erosion, it can also impact the quality of the water.   Remember the bathtub analogy — everything in the tub gets rinsed off and the dirty water gets washed down the drain. In a watershed that includes rinsing off roads, lawns, fields, roofs, barnyards, parking lots — everything! Whatever we put on the ground has a good chance of ending up in the creeks and streams which provide drinking water and habitat for lots of people and critters.

There are three main forms of pollution affecting the health of the Roanoke & James Rivers — excess nutrients, toxic substances such as chemicals and heavy metals, and too much dirt or sediment suspended in the water.⁵⁶ These pollutants come from all over the watersheds, including from the Catawba Valley. Like anything, any of these substances are okay in moderation, but when we have too much in the water, it can cause big problems for fish and wildlife, as well as for humans living on and drinking the water, both here and downstream.

Nutrient pollution includes things like nitrogen and phosphorus, which come from sources such as fertilizers, manure, and septic tanks. These nutrients are important for plants, but when too much ends up in the water, it can trigger big algae blooms. The algae blocks sunlight from getting to the bottoms of rivers and creeks where plants need it to survive. Then, when that algae dies and decomposes, it uses up a lot of oxygen in the water, causing “dead zones” where there isn’t enough oxygen to support life.  Both the James and the Roanoke Rivers are considered “impaired” because of high levels of nutrient pollution, mostly from wastewater treatment plants and agricultural operations not using Best Management Practices (BMPs).⁷ We will talk more about BMPs that can be implemented to prevent nutrient pollution in the Land Management section.

We generally associate toxic and chemical pollutants with factories or landfills, but they also come from sources like pesticides, road run-off, and air pollution.   These contaminants in the water are often harmful to fish and human health.  Water tests from the James and the Roanoke Rivers show that both of these rivers have harmful levels of mercury and PCBs.⁸  We can keep these toxics out of the water by making sure we apply and/or dispose of farm and household chemicals properly, and reducing our consumption of coal-fired electricity.

Sediment gets into the water from streambank erosion as well as from dirt running off the land into creeks and streams.  While we typically don’t think of dirt as a type of pollution, when there is too much dirt suspended in the water, it can have harmful effects on water quality and stream ecosystems.  Dirt in the water decreases the clarity of the water, making it difficult for sunlight to reach the bottom and provide plants with necessary nutrients.  In addition, when the dirt settles, it covers plants and rocks that bottom-dwelling creatures may rely on for habitat.

Another pollution problem effecting water quality in the Catawba and North Fork Valleys is high levels of bacteria, specifically E. coli, in the water.  This bacteria typically comes from animal waste, including wildlife, humans, and livestock and can create health hazards for humans.  Both Catawba Creek and the North Fork in these areas are listed as impaired waters by Virginia’s Dept. of Environmental Quality for high bacteria levels.⁹

Learn More

• For resources and tools on managing your stream, go to the Landcare Toolbox
• To learn about the ecosystem supported by our creeks and streams, go to the Ecosystems section
• To learn about managing creeks, streams, and the land around them, go to the Land Management section
• To learn more about the environment of the Catawba Valley, go back to Our Valley – Environment
• To learn more about Catawba Landcare projects to improve the creeks and streams health in the valley, and to get involved, go to the What’s Going On section

1. Roanoke River Basin Association – Basin Facts [↩]
2. Environmental Defense Fund – Albemarle Sound [↩]
3. James River Association — James River Watershed [↩]
4. Chesapeake Bay Program — Bay Pressures [↩]
5. Chesapeake Bay Foundation — Roanoke River Fact Sheet [↩]
6. Chesapeake Bay Foundation — Upper James Fact Sheet [↩]
7. VA Dept. of Environmental Quality — 2008 305(d)/ 303(d) Water Quality Assessment Integrated Report [↩]
8. EPA – Mid-Atlantic TMDL Program - PCB Watershed TMDL [↩]
9. VA DEQ — 303(d) Impaired Waters List — James River Basin and Roanoke River Basin [↩]