flash board riser vs. pvc

[Island Hunter]

Wanted y'alls opinion on something. We got the pumoing situation figured out with our swamps, we are going to buy a diesel pump that is portable. Now we are trying to figure out how to control water flow. We have been damming the water with sand bags but we need a more reliable method. Would y'all recommend using a flash board riser outlet or gitting large diameter pvc and putting a 90 degree elbow on it and having different length pipe to fit in it. Just wondering if y'all had any input. Thanks in advance.
Robert

[Palmetto Pride]

Flashboard riser. PM me if you need details on the SC DUCKS special discount.

[Aging Baby Boomer]

It depends on how much you want to invest and how permanent you want your setup to be. PVC with a bend and riser will be significantly cheaper. But - PVC can split or crack over time. It's subject to UV damage where exposed. And beavers just love chewing on PVC pipe that is used to impound water!

Flashboard risers make it easier to adjust water levels (especially after you have water in the pond) and are more permanent if you use good materials. The down side is a flashboard riser will be more expensive.

From personal experience - If you're working with low pH water (anywhere in the Lowcountry!), steel pipe can rust out in a few years even if it's galvanized and tar coated. Aluminum pipe and riser (not aluminized steel) will provide the most permanent installation. We have one that's been in service for 26 years with no sign of deterioration.

If you have access to a backhoe, the riser/pipe will be accessible, and you don't mind replacing it occasionally, PVC may be the answer for you. If not - I'd suggest an aluminum flashboard riser.

[Birdfinder]

Agri Drain

[Sasha and Abby]

Riser boards... just wish we had some ducks.

[Candor]

riser. Do it right and do it once. Make sure you get the riser sized correctly for your pond/drainage area. Investigate the proper way for installation (ie concrete/weight requirements for the riser, dike slope for your soil conditions) make sure you do an overflow area that is stable.

[deadriver]

Riser board is easy to use, not the cheapest. PM me with a rough idea of acreage in drainage area and where you are, i can quickley give you a design flow for your main outlet (the riser). Make sure you plan for some type of secondary outlet for high flow periods (ie:20 year to year storm).

[Palmetto Pride]

Schedule 40 will be more resistant to UV rays and yellowmine would be a more permanent solution and is relatively in expensive unless you have a tremendous amount exposed. You can attach yellowmine to PVC with the correct couplings and avoid any leaking of the joints.

[Chessie Dog]

If interested in water control devices, ya'll can give me a call @ 843-760-4540. I work for a company called CFP and carry all of the Above. I can get alot cheaper than Agridrain. We carry Corrugated Metal, HDPE and PVC. I have helped the state build many of there Impoundments including Bonnue Ferry. IF it includes some duck hunts, I can get a whole hell alot cheaper than anyone.

Thanks,
Brian

[Island Hunter]

Sorry it has taken me so long to get back to y'all. I have been working the past two days. We will be flooding roughly 20 acres. I think we are going to flood it to about two feet deep from november through march and then pull the water level down to promote aquatic growth during the rest of the year. Thanks for the input I would rather do it right the first time.
Robert

[deadriver]

To give you a feel for your draw down time of 40 acres, for a 6 inch pipe as a drain, 7.5 days; for 1 foot pipe as a drain - less than 2 days. For the flashboard, 18 wide and average flow depth of 1 feet over the drainage period, a little over 4 days, drop that size to a foot and it is over 6 days. A 2 foot D riser board drains it in less than a day.

Rough figures based on average flow depths just to give you a feel for sizeing the riser. PM if you need more than that.

[Aging Baby Boomer]

Deadriver's suggested pipe diameters are good unless you have beavers in your area. If you do, bite the financial bullet and increase the diameters by 50% to 100%. A quick drain at season's end is important for discouraging muskrats and beavers from using your dikes for den sites.