Meanders
A meander, in general, is a bend in the river. A meander forms when moving water in a stream erodes the outer banks and widens its valley, and the inner part of the river has less energy and deposits silt. A river, like the Brazos, with any volume of water may assume a meandering course, alternately eroding sediments from the outside of a bend and depositing them on the inside. The result is a snaking pattern as the stream meanders back and forth across its down-valley axis.
Brazos River
The Brazos River begins at the confluence of the Salt Fork and Double Mountain Fork in the high plains of the Llano Estacado and flows 840 miles through the center of Texas. The Brazos River is dammed in three places north of Waco forming Possum Kingdom Lake, Lake Granbury and Lake Whitney.
Before and after the American Civil War, steamboats traveled as far north as Washington-on-the-Brazos. Improvements in transportation, such as railroads, made the need to navigate the Brazos River unnecessary for steamboats or other large ships. Today, the Brazos River’s water is used for power, irrigation and recreation.
Oxbox Lakes
Over time as the Brazos River has flowed from the Llano Estacado towards the Gulf of Mexico through central Texas bends in the river have occurred. Over time, these bends have been cut off and an oxbow lake was formed. To complete the transformation from a bend or U shape in the river to an oxbow lake, erosion and deposition is needed along the banks of the Brazos River. Over time, the erosion action on both sides of the bend or U join together and silt is deposited at the mouth of the U, closing it off from the Brazos. Without the Brazos River flowing through this meander, the oxbow lake is formed. Near the location of this Earthcache there are several oxbow lakes to the northeast.
Rip Rap
Rip rap is rock or other materials that are used along rivers, shorelines or are used to create jetties. Rip rap serve as a foundation or sustaining wall along an embankment to prevent erosion. Rip rap is made of a variety of types of rock or other materials such as granite, limestone or concrete rubble.
To claim your Earthcache go to the following coordinates and answer the following questions, and send me a message with the answers. Logs that do not submit the answer will be deleted:
Go to:
N 30 07.767
W 96 11.179
- What type of material is under your feet to prevent erosion of the bank and the collapse of the bridge support?
- Using the bridge support to your right, estimate how many feet tall these supports are. Use this height to estimate the distance across the Brazos River from shoreline to shoreline at this location.
- Do you think the Brazos River over time has become narrower or wider? What might be a reason for this?
Now go to the second location:
N 30 07.793
W 096 11.189
- From this location look north. Does the Brazos River appear to be narrower or wider than the first location? What might be a reason for this?
- Looking north at riverbank on the east side, is the riverbank being eroded or having sediment deposited?
- Looking back to the first location, estimate how many feet tall the bride supports are. Use this height to estimate the distance across the Brazos River shoreline to shoreline about 100 yards north of your location.
- Describe the speed at which the Brazos River is flowing. What might the effect of this speed have on the riverbanks?
Required: Send your answers to the questions before logging a find.
Optional:
Post a picture of your GPS unit or smartphone with the Brazos River in the background.