The pond in my front yard is only about 100-125 feet diameter and about 10 feet deep. It has a large fountain on it for aeration. From the pictures you will see that the pond side of the culvert is lower than the discharge side where it overflows. I think originally it was to flow from the discharge side to the pond for drainage. In order to raise the pond level an elbow was added to the pond side culvert so that the water would raise to the top of the elbow before leaving the pond. The weight of the elbow separated it from the culvert pipe so now it floods the overflow area before raising the pond level. I think the integrity of the 24 inch culvert is okay since it only carries water away from the pond if the pond overflows (that is if the elbow is sealed to the culvert pipe). The elbow has pinholes in it and was placed on the culvert a couple of years ago, it was a used rusty used elbow is what I was told. Due to the cost and it being hard to find I would like to replace the 24 inch elbow with a smaller one, however, connecting a 24 inch pipe to a smaller one is actually more expensive for the reducer. I thought of using a smaller PVC pipe that would go inside of the 24 inch and then sealing it with waterproof grout? About the largest elbow I have found is 6 inches... would that work just to raise the water level? Thanks for any help ! James
https://lh6.googleusercontent.com/kSBD0Bnd0oxWDGP0CNXC5WtbCtbVsCFk6Twugx6H0k8=w284-h188-p-no
https://lh4.googleusercontent.com/7GXANtG5mkkcv8bW91dFOe0CAO_RcUKMV5OTdT_aR90=w285-h188-p-no
https://lh3.googleusercontent.com/ei9Fih6KI79axVoEHnAqo5xPgfooSmZDpedyq1WW4Wk=w285-h188-p-no
https://lh6.googleusercontent.com/_GT0desYfTjiNTikei5-Fe_J83JtZVgv4jov6ZLaZLE=w285-h188-p-no
https://lh4.googleusercontent.com/UC3GW-NCUNCywviuerxhi4tDt-etHWE_A0k3MuY4lKs=w285-h188-p-no
https://lh6.googleusercontent.com/e56vGmuPL6pWGOqXObtO5dHdFYRrt1JEI_73rWvRJQg=w284-h188-p-no
https://lh5.googleusercontent.com/6D_opVJRutFz-OfRaLWh5dE-f-Oa-m-Y805tE4R0iJM=w285-h188-p-no
https://lh3.googleusercontent.com/wSJhXgO6yXFaM0pJ0-zKqUkAGSbVdYLxwrkemxc9LmU=w285-h188-p-no
https://lh4.googleusercontent.com/pb-dwvTaY-72Iln5936mohMlpsFmWOAYIn4l3j4whuw=w285-h188-p-no

James, welcome to the forum.

First question, where does the water come from that fills the pond with the fountain?

Thank you for the welcome !

Rain water when we have it and water well to maintain the level, it hasn't rained much and I stopped adding water to lower the level so I could work on this.

The smaller PVC pipe would work IF it's large enough to handle the amount of water from a storm. How big does it need to be? I can't answer that (you really should plan for 50 year and 100 year storms) but I can point you in the right direction.

Find the NRCS Office for your county. http://www.nrcs.usda.gov/wps/portal/nrcs/sitenav/national/states/

Call them and make an appointment (it may not be needed) to talk to someone there. They can do the calculations for you on the amount of watershed feeding the pond, and what size pipe you would need to handle the amount of water you could get from a large storm.

Thank you, I have found their office information and will contact them. I would be happy to go larger than six inch diameter on the pipe if I can find a source in North Texas. Again Thanks

Yes, I'd go with the largest diameter pipe possible.

I offer some thoughts here with a couple of sketches. I've pondered over an idea similar to yours before, but have never implemented it. The 2nd sketch shows a way to raise the height of the intake without having to use an expensive pipe fitting.