•Do not place the following items in the cache: food, inappropriate, offensive,
or hazardous materials.
• Absolutely no cutting of brush or other vegetation is allowed.
• Visitors must remain on designated trails.
• It is the visitor’s responsibility to orient themselves with the rules of the
District site.
• Sites are open sunrise to sunset, however some gates may not open until 8am.
• At certain times of the year, sites will close for a variety of reasons- it is illegal
and dangerous to enter at these times.
This EarthCache is a lesson in river/stream Hydrogeology. When I learned how to flyfish an important lesson was how to “read” a river/stream. This had to do with the surface of the water. What happens on the surface is dictated by what lies beneath. On your quest to log this EarthCache, you too will learn how to “read” the river/stream. It is strongly advised to have access to the questions and terms as you travel from reference point to reference point. Total time should be under 1 hour. Total walking distance is less then 1 mile. The distance between the 2 parking areas is about 1 mile. There is a grass trail for you to follow from both parking areas to make your observations.
The following is a list of terms and descriptions about the features of a river/stream:
Confluence: The area where 2 rivers/streams flow into 1 channel.
Rapids: Fast flowing segment of a river/stream. Characterized by having large boulders and a drop in elevation and possibly a constriction in width. The water flow here is extremely turbulent and only the larger boulders are able to hold their place due to the fast current flow.
Meander: When a river/stream reaches base level it meanders. Base level refers to little or no drop in elevation. The flow here is slow and steady. The river/stream winds it way along looking like a snake.
Riffle: An area along the river/stream characterized by having small irregular waves. Usually forming at the tail of a pool. The current here is faster and the streambed has larger gravels and cobbles. The flow over these causes the riffles. The increase in flow is caused by the decreasing depth. Riffles are a shallower part of the river/stream. Riffles can be 6 inches deep or a few feet, depending on the overall size of the river/stream.
Pool: The deepest part of a river/stream. The upstream side of a pool is called the head, the downstream side is called the tail. The pool is characterized by having a slow, glasslike flow at the surface. Much of the water flow is in the lower depths. This flow is what causes the gouging out and deepening of the pool.
Backwater Eddy: An area along the side of a river/stream containing slack water. As there is little or no water flow, the bottom here is muddy or sandy. The lack of flow causes the river/stream to drop the smaller particles of its sedimentary load. It is sometimes characterized by having a circular motion.
Run: A run is a section of the river/stream that is deeper, but not as deep as a pool. The flow here is steady as the channel is wide and has relatively few obstructions along its bottom.
Floodplain: The area along a river/stream that in times of extreme flow backs up and floods. The excess water is held on the floodplain until the channel recovers and can alleviate the excess water.
Bank undercut: When the adjacent land is cut away beneath its surface. This formation usually occurs when the river/stream makes a turn. The outside and inside bend of the turn carry about the same cubic foot amount of water. The outside turn has a longer way to travel and due to this the flow is extremely faster, the inside of the turn which has a shorter distance to travel has a slower flow. The faster flow on the outside of the turn deepens that edge of the river/stream and cuts away eroding the bank.
In order to log this EarthCache as a find you must email the answers to the questions below, using the above terms. We request that you email the answers with 48 hours of your log entry. We reserve the right to delete any “Found It” logs for lack of emailing the answers. DO NOT PUT THE ANSWERS OR PICTURES AT THE REFERENCE POINTS ON YOUR ONLINE LOG!!!
Its time to use your powers of observation and understanding of the terms above to complete this Earthcache. Here are 14 questions for you to answer:
A) At reference point #1
- What feature is in front of you?
- What feature is upstream?
B) At reference point #2
- What feature is in front of you? What stream bed geology causes this to occur?
- What feature is directly to your right? What type of sediment is on the stream bottom? What causes this sediment to occur here?
- What feature is on the opposite side slightly downstream? What causes this feature to occur?
C) At reference point #3
- What feature is located here?
D) At reference point #4
1) What river/stream feature is upstream and downstream? Why do you think it occurs here?
2) What feature is the adjacent area?
E) Reference points #1-4 inclusive
- After completing all your observations what river/stream feature is NOT here?
Thank you for visiting our first EarthCache!
Congrats to Honeybee77 for the FTF!