Need help developing an Earthcache...

[+Okiebryan]

We have a public water supply reservoir that is fed by a major river. (search Lake Overholser on Google Earth or Maps.) It's the oldest lake in the state. The way they built it is unique in that there is a diversion canal and split dam design. River water bypasses the reservoir normally through the canal and the side of the dam, where it goes on downstream.

 

When they want to add water to the reservoir, they restrict the flow on that side of the dam, and back water up in the canal. At the beginning of the canal, there is a rollover with many acres of wetland plants through which the water must pass to get to the actual reservior. The rollover only allows canal water to spill into the lake when the height reaches a certain point.

 

I know that this wasn't accidental, but since this was all constructed in 1918, I'm having trouble figuring out just how much of this was foresight and how much was a fortunate accident. I know they probably set this up to de-silt the water...Okie rivers get pretty silty. However, now we have a filter for phosphates and fertilizers. I doubt they knew about such things in 1918.

 

This is the problem. There is no monument to what's happening here. I can't think of what to have people do to complete an Earthcache to show they lernt sumpin.

 

Ideas? I've never set up an Earthcache.

[+catsnfish]

How about collecting a small jar of river water and a small jar of reservoir water, filter each through a coffee filter and compare residue amounts on the filters. They could post a pic of the 2 filters and/or describe their findings. And the required photo of course

[+GEO WALKER]

Just a thought or two...

I’m not sure if there are walking paths thru the nature area, but you may want them to head N of the highway and observe the river in its natural state and then bring them back to the lake area. The lake seems to me to have a double purpose, one for community water supply and the other flood control.

 

You may want to build the EC on flood control. Explain to them the diversion channel and the tributaries that seemed to have been converted over into canals. Ask them w/o this what areas of town may be effected by a flooded. Is there nay history of flooding in this area prior to the construction of the dam?

Is there a USGS Gauging Station nearby w/a web page reference? If so, what is the normal river or dam level at the time of their visit? I’ve noticed more and more USGS Gauge Station ECs popping up. This is a good way to learn the importance of these stations and flooding.

 

You may also what to build this from a sedimentological standpoint. I noticed a number of meanders N of the dam. Perhaps a lesson on meander sediment deposition or stream flow might work.

[+Okiebryan]

The canal that goes to the northeast is not a trib. It's a man made canal that takes water from the river and carries it to Lake Hefner, another public water supply reservoir. This canal is the only source of water for Hefner.

 

Keep the thoughts coming... I'm getting some ideas that I hadn't thought of, and I feel this starting to come together.

[+Okiebryan]

Actually this was built in 1918 when OKC was 10 miles away. It was built for one purpose. Water.

 

In 1936 the dam overtopped and broke, which emptied the reservoir and flooded OKC. It was a disaster of unbelievable proportions. They rebuilt it better and it has not happened again.

 

Actually I'm more interested in the function of the wetlands above the reservoir. There are no trails through the area north of the highway, just in the perimeter of the area which is now a wildlife refuge.

 

They flood that area a lot, and it is really hard to get to the actual river in that area most of the time. There are quite a few caches in Stinchcomb (the wildlife refuge north of Route 66), and most cachers have "been there done that" and it's a little hard to get people to go in there.

[+catsnfish]

wetlands manmade models I have to agree, the filtration the wetlands provides is quite interesting. If you do a search on elementary education, wetlands, you can find several experiments ranging from simple to complex. If there is a ph difference between the river and the reservoir, a litmus test could also be used.

[+DeRock & The Psychic Cacher]

As others have noted there are sereral approaches you could take to make this an EarthCache

 

If you're keen on the wetlands and the de-silting this could be an erosion feature.

 

For your logging requirements there are several possiblities:

 

1. Observe a location above the dam/reservoir where silt is entereing the water (could be a bend in the river) and visually record measurements (width, depth, or length of the bend). North Morgan rd just west of the turnpike would work. Looks like it dead ends right into the river at a bend.

 

2. Gather soil near the dam/reservoir. Add some soil to a glass/plastic jar and shake it and observe the results (layers of sediment) after a few minutes/hours/or days? and report the findings.

 

3. Gather water from the river (above the dam) and take a sample. Let it settle overnight and report the findings. Looks like where Canal rd hits Rt 66 there is a small bridge that could work for this.

 

4. Gather water from the reservoir and take a sample. Let it settle overnight and report the findings. Lake Overholser park would be a good spot.

 

I like a combination of #2 and #4. This would show the effects the wetlands have on silt removal. This could all be done at Lake Overholser park. All you need is permission.

 

Not to give you too many options but ....

 

The city seems to have a park planned for the Stinchcomb Wildlife Preserve. Here is a webpage that talks about it and the importance of the preserve as a filtration element for water: City plans for park.

 

Just a couple of months ago they approved a plan for the park: Park Plans

 

This seems like the idea place to put your EarthCache. These folks would understand the importance of what you are trying to do and would be the most favorable to seek the all important permission from. Some good contact names in the documents too.

 

Here is another webpage that talks about the Refuge and has a picture of the gaging station that is located underneath the dam (another EarthCache possibility- river feature) and talks about access to the preserve and even mentions the geocaches currently located there.

 

Deane

AKA: DeRock & the Psychic Cacher - Grattan MI

[+Okiebryan]

Wow, I'm amazed at the level of research you did with nothing more than Google and maps.

 

I know about the proposed park. My employer is trying to get some surveying work on this project. However, it's going to be another year or two before this gets built.

 

You have given me some great ideas. I'm going to read some more and sleep on this.