Storm runoff yesterday offered some good examples of how increased water flow changes the stream course. Water above the dam is temporarily slowed by the obstruction. Water velocity increases as it is forced through a narrower opening and increases again as it rapidly falls to a lower elevation. Turbulence combines with the increased speed and the water is able to change the shape of the downstream channel.
The turbulence from the fall travels as waves of energy down the stream bed. Water striking the streambed is deflected upward where is can again fall. These energy pulses effectively knock pieces of loose materiel up into the water column where they can be washed away.
The water’s energy is directed to the bank on the outside of the curve. The bank suffers a little bit of erosion each time this happens. This increase in flow was produced by 1.25 inches of rain in a 12 hour period. Streams are subjected to this type of flow several times each year and are subtly shaped by the action of the water. Out of bank flood events are a much rarer occurrence and have a different effect on the stream.
Obstructions, such as the fallen tree, add to the complexity of the flow pattern. This obstruction is causing the water to accelerate through the narrow opening to the right and is causing an outward bow to the stream bank.
Two tributaries join in the center of Blue Jay Barrens. Both of these tributaries begin on neighboring properties and the water quality is a reflection of the activities taking place on those properties. The stream on the left always exhibits a higher degree of turbidity.
The amount of sediment attributed to stream bank erosion is minimal. The sediment shown here is a result of poor upland soil condition and cover. There are a few small watersheds that are entirely contained within Blue Jay Barrens. The clear water entering from the right is from one of these watersheds. Proper land management could allow these streams to flow clear despite the amount of rain received.
Storm runoff yesterday offered some good examples of how increased water flow changes the stream course. Water above the dam is temporarily slowed by the obstruction. Water velocity increases as it is forced through a narrower opening and increases again as it rapidly falls to a lower elevation. Turbulence combines with the increased speed and the water is able to change the shape of the downstream channel.
The turbulence from the fall travels as waves of energy down the stream bed. Water striking the streambed is deflected upward where is can again fall. These energy pulses effectively knock pieces of loose materiel up into the water column where they can be washed away.
The water’s energy is directed to the bank on the outside of the curve. The bank suffers a little bit of erosion each time this happens. This increase in flow was produced by 1.25 inches of rain in a 12 hour period. Streams are subjected to this type of flow several times each year and are subtly shaped by the action of the water. Out of bank flood events are a much rarer occurrence and have a different effect on the stream.
Obstructions, such as the fallen tree, add to the complexity of the flow pattern. This obstruction is causing the water to accelerate through the narrow opening to the right and is causing an outward bow to the stream bank.
Two tributaries join in the center of Blue Jay Barrens. Both of these tributaries begin on neighboring properties and the water quality is a reflection of the activities taking place on those properties. The stream on the left always exhibits a higher degree of turbidity.
The amount of sediment attributed to stream bank erosion is minimal. The sediment shown here is a result of poor upland soil condition and cover. There are a few small watersheds that are entirely contained within Blue Jay Barrens. The clear water entering from the right is from one of these watersheds. Proper land management could allow these streams to flow clear despite the amount of rain received.
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