Pond Boss
Posted By: Pondwish Winter drawdown? - 12/16/17 03:12 PM
2 year old, 1 acre bass-bluegill pond in E Tx, max depth 13 feet with steep slopes. 50 acre watershed with feeder creek/spring.
I recently read about the practice of a winter drawdown and how this can concentrate forage for bass to eat easier as well as drying out/killing off unwanted vegetation. I have a lot of filamentous algae right now and I have a lot of silting in especially at the upper end of the pond. Its looking like a dry winter so I'm considering drawing the pond down 2-3 feet (I have a valve on the backside of the dam) then cleaning out the algae and some silt after it dries up. Hopefully plant some grass or something to prevent erosion when the rains come. Does this sound wise and possible?
Posted By: Dave Davidson1 Re: Winter drawdown? - 12/16/17 03:51 PM
Yes, that will work. However, I find a bigger problem in bass over eating the food supply in a 1 acre pond.
Posted By: FireIsHot Re: Winter drawdown? - 12/16/17 08:31 PM
Pondwish, I can't give you any advice, but I will share my experiences with drawdowns of our 1/4 acre hatchery pond, which we can refill as needed, and droughts on our 11 acre pond.

During droughts, we cull our LMB very aggressively. Since the water's pinched, it's basically increasing the pounds of predators per acre of water. More predators per acre, means more competition for available food, and forage that's lost a great deal of protective cover.

We always get as much dead vegetation and dry FA out of the pond as we can during droughts. Fall droughts are always the best for us. Vegetation's still actively growing, and not only do we try get the dead stuff out, we treat still growing plants now that the shoreline has moved. Cover is added, and aggressive LMB culling takes place too.

Summer droughts or dropdowns at least give the forage a change to reproduce. A late fall or winter drawdown means no potential recruitment for 5-6 months, so there's a constantly declining forage base for that period, that becomes much easier for predators to catch with the decreased water level.

We've had the best luck with problematic shoreline vegetation that needs to be removed by either getting a Caterpillar in here while the water level's dropped due to a drought, or treating the plants with recommended herbicides while they're actively growing. If we didn't do one of those 2 things, tubered plants, or those that spread by rhizomes like American lotus or waterleaf often came back the next spring. The only exception to all that has been FA. It's an ongoing problem here.

At this point, If I wanted to do a water drop, I would not drop my big pond more than a foot or two, and wait see what spring brings. We've had a tremendous amount of rain over the last 3 years, and I'm not convinced that will continue.

In our 1/4 acre pond, we do drawdowns several times a year to manually remove plants, do bank maintenance, or pinch the water prior to seining it.

We always draw water from the bottom of the pond. As a rule it's the least desirable water, and removing the top 3' of the water that the fish reside in, doesn't make sense to me. When we refill the pond, we float the pipe outlet so the fresh water is released at the top.

We leave water primrose in the 1/4 acre pond to serve as fry cover for whatever we're growing that year, or for the forage used to feed them. During drawdowns, that cover is removed and the smaller fish are easy targets. That is exactly what we want, because historically the smallest fish are the only ones that struggle during movement from one pond to another. Our predators gorge during this same period.

Finally, we've kept the 1/4 acre pond lowered 3' for as many as 2 weeks, and quit supplemental feedings during those periods. I do not have aeration, so I rigged up a siphon aerator out of one of my pumps, and ran the pump 4 hours a day, every other day to help with any potential O2 problems caused by the relative biomass increase. When we seined the pond at the end of those 2 week periods, 80% to 90% of the forage that was eatable(gape friendly) by the fish I was growing out at that time was gone. This has held true with whatever omnivore or carnivore I was raising at the time, including tilapia. Obviously there's a higher predator rate than is recommended (we normally stay at double the recommended rate per acre when growing out fish), but even at 50% of that number, 40% to 45% eaten maybe?

PW, I love drawdowns and think they do have merit. It's just that Mother Nature has had me crying uncle a few times, and I'm leery of releasing water I can't replace.

If you have any questions, ask away. Somebody should have some help.
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