Flooding Impacts

By Dave Sligh


The James was overflowing its banks in a number of places yesterday and many tributaries were roaring in the last several days, with some localized flooding. I'm thankful that I didn't see or hear of any human injuries or death. However, there was lots of damage done to stream channels because of the high flows. It's natural that periodic floods rearrange stream banks and habitats - in fact it's an essential process in the life of the stream. Our activities on the land though cause changes that aren't within the natural range and aren't beneficial.

The first photograph below shows a portion of a stream that I've observed over the last year. While this small section of the stream bank was already eroded and cut down to form a vertical wall of dirt, the recent high waters ripped away all of the dirt in this large depression. I'm not too experienced at estimating amounts of dirt but would guess that at least several tons of soil was carried downstream from a length of stream reaching no more than 100 yards. If you recognize that similar erosion effects occurred in dozens of other places on this same stream and multiply this by the thousands of small streams throughout the James River watershed, you can see the enormity of this problem.

You can see in the second picture (below) the stream bank across from that in the first view. This slope was covered all the way to the top of the slope with large stones (generally known as rip rap) in an attempt to stabilize the portion nearest the adjacent road. Almost all of the stones were washed away during this storm, showing that our human attempts at channel protection are sadly inferior to natural vegetative buffers and land cover.

This small tributary to Ivy Creek, in Albemarle County, is less than one mile in length upstream of the point shown in these photographs and this portion of the stream drains an area of about 0.5 square miles. The land is primarly in pastures with scattered home sites and a relatively small percentage of impermeable surfaces. However, the stream-side vegetative buffers are completely missing or very narrow along at least half of the stream's length. That this small watershed with primarily agricultural land can produce such force and destruction illustrates the extreme importance of maintaining stream buffer plantings and re-establishing them.

Finally, you can click on the link below and see a short news segment from Channel 19 TV in Charlottesville where I was interviewed describing this type of damage from high flows.




http://www.newsplex.com/video?clipID=4490640&autoStart=true&contentID=82706652

Flow Patterns in the James

By Dave Sligh

I've been looking at stream flow records during the last week to understand effects of human management and storms on stream flows in the James River basin. The graphs below show recent flows in the Jackson River, the stream which joins with the Cowpasture River to form the James, in the mountains of Alleghany County.

Releases of water from Gathright Dam control flows in the Jackson River and in the James River for a considerable distance downstream under many conditions. However, we can see that the effects of this recent storm has overridden the influence of the Dam. The first graph below shows that stream flows were maintained at a stable, low level below Gathright Dam through controlled releases by the Corps of Engineers which operates that dam. In contrast, the flows rose very sharply in the Jackson River at the stream gage below Dunlap Creek at Covington.

Flows rose very quickly in the Jackson during a 9 hour period, with an increase of over 400%. Several factors likely contributed to this drastic increase in flow over such a short period. Consistent rains in recent weeks have contributed to saturated soils so that much of the rainfall runs off the land rather than soaking into the ground and the steep mountain slopes in this area can contribute to rapid rises. Finally, there are fairly large percentages of impermeable surfaces (streets, parking lots, buildings, etc.) in the Covington area. To assess the relative contributions of these factors, we can look at storm-related flows during other times of year when the soil is drier and more likely to hold a larger percentage of rainfall that lands on vegetated areas.

I and others plan to make a long-term study of the effects of Gathright dam releases on the James River system. Wherever human actions and structures affect a natural system, we must periodically consider whether these factors can or should be altered to provide for better water quality, for competing human uses, and for the overall natural balance of the stream ecosystem.

Big Challenges For the James and the Bay

By Dave Sligh

I attended a meeting yesterday with citizens and officials from the Rivanna River watershed who are trying to see if they/we can help determine the way that EPA's newest efforts to protect the Chesapeake Bay can and should be applied in the area. I hope this effort can be a model that other citizens in watersheds throughout the upper James basin might emulate, because it could help local folks be more committed to following-through on the implimentation of pollution control plans. These plans are designed to benefit the Bay and all of the downstream resources but can and must correct significant problems from sediment and nutrient pollution in waters throughout the headwaters and Piedment areas of the James watershed.

If you don't yet know about initiatives that EPA, the states, and groups like ours are involved with to finally move Bay restoration forward forcefully, you might be interested to read some of the background materials. One good place to start is the Virginia DEQ's site at: http://www.deq.state.va.us/tmdl/chesapeakebay.html/chesapeakebay.html. We'll working to keep you up-to-date on these issues in the coming year or two and will need your help to support strong, specific cleanup goals and vigourous enforcement. Please also check out our brand new "State of the James" report - our report card on the River and its tributaries (http://jamesriverassociation.org/the-james-river/state-of-the-james/).

Finally, I'll leave you with a view of the Rivanna River this past summer, to remind you of the kinds of impacts an over-supply of nutrients can have on local streams.
























The solid-looking masses you see in the Rivanna are not rocks but large clots of algae that made the stream unpleasant for human use and are a symptom of water quality problems.

A Beautiful Year - More To Do

By Dave Sligh

As we near the end of 2009, I am thinking back on the many experiences I have had throughout the upper James watershed. I have met hundreds of people who care about and know about the River and its tributaries and who will be great allies in the years to come. We achieved some important advances on regulations to better control pollution from construction sites, poultry waste transfers, post-construction stormwater, and industrial runoff.

Below Falling Spring Falls, Alleghany County

Best of all, during the past year, I have seen so many beautiful sights throughout our area and I am including some of my favorite photos here as a holiday season gift.

Under Swinging Bridge, Craig Creek

Cool Pool on West Fork Tye River

James River, Botetourt County

High Water on the James

By Dave Sligh

Last Thursday, the James was flowing high and full. The photo above shows the area that usually serves as the parking lot for the Scottsville boat ramp. I saw large logs and pieces of wood continually streaming by, out in the middle of the stream. I also visited sites downstream as far as New Canton, and the River was also lapping up into and over boat ramps and parking lots at other sites.







Some data on this high flow event:

Peak flow at Scottsville:
43,000 cubic feet per second (cfs)

which equals 28 billion gallons per day.

Median flow for this time of year:
2,000 cfs

which equals about 1.3 billion gallons per day


The stream flows in the James River climbed from 7,670 cfs at 10:30 p.m. on Dec. 8th to 43,900 cfs at 6:30 p.m. on the 10th.
An increase of over 570% in 44 hours.

By contrast, the Rivanna River at Palmyra rose from 1,060 cfs to a peak flow of 17,500 cfs in a much shorter time.
An increase of 16,500% in only 26 hours.

This steeper rate of increasing flows in the Rivanna is likely due, at least in part, to a higher percentage of developed and impervious surfaces in this watershed than in the James River watershed above Scottsville.

Falling Springs

By Dave Sligh



Last week, Bill Street and I visited an area of Alleghany County that more people should know about. The waterfall shown above, Falling Spring Falls, is of both ecological and historical significance.

According to signs at the site provided by the Virginia Division of State Parks, the stream that flows over the falls begins in Warm River Cave, north of this point. Warm thermal spring water mixes with a seperate stream of cold groundwater in the cave. The water is supersaturated with carbonate and creates formations of limestone, like those at the base of the falls. Below the Falls, in areas where rocks are continuously moistened by spray and water splashing, a unique community of organisms, including moss and bryophyte species survives in an environment considered to be rare in Virginia.

Historical features of the site include a visit to by Thomas Jefferson to survey the falls and a mention in Jefferson's 1781, Notes on the State of Virginia. Electrical power was first generated when the force of water from the Falls was harnessed by piping it about a mile down the valley to a power plant. This plant has recently been re-opened and is again generating electicity.

Falling Springs Run eventually feeds the Jackson River after winding its way down through a narrow valley. The picture below shows the stream just above where the streams join.

Posted by Chuck Frederickson

Quite a storm for "just a nor'easter". I talked to one of my friends in Pequoson and he told me that the water at his house on Friday was within five inches of the the Hurricane Isabell level. If we would have had Isabell's sustained winds, it would really have been a mess. I went on a short tour yesterday and was pleased to see that there did not appear to be much damage from the storm. The river was still running high and there was a lot of debris but all in all, not too bad. It's not the logs floating on top that worry me, it's the one that is about six inches below the surface that you can't see that will take out a lower unit. Just be careful out there.