As autumn rolls around promising cold weather and ice, it's easy for pond owners to file away thoughts of pond activities. But there are plenty of good things to do for your pond come fall, some optional, some to ignore at your own risk.
Pond Cleanouts Here in the east, and across the country in fact, it's a dry year. And dry years are especially good for pond cleanouts. Cleanouts (usually by excavator, perhaps dozer) are called for when ponds get in trouble with excessive vegetation (read pond weeds). Also, older ponds fill with sediment and lose depth, which a cleanout will restore. Excess sediment can also create deficits of dissolved oxygen, which can hurt fish and inhibit natural decomposition of organic matter on the pondbed. In dry fall weather, cleanouts go well because inflows and static water levels are low. That means it's easier to drain or pump out the pond and then keep basin water down, during the work. Dry weather means the pond is generally less vulnerable to shore area damage by heavy machines. Doing cleanouts in the fall takes the pond out of commission during a low use season, and gives the pond all winter to refill.
Spillway Maintenance Fall is the time to make sure your spillways will function properly during the cold months ahead, when you might not be paying attention to the pond, and when heavy rains and snowmelt and ice can stress spillways. If your spillway is a pipe system, make sure the inlet is free of weeds and debris. Sometimes dead leaves and weeds can pile up around the standpipe inlet, and should be cleared away. If you have a trash guard on the inlet, make sure it is trash free, and stable. You don't want the inlet to be plugged up in any way, reducing spillway ability to discharge overflow. Same goes for the outlet/discharge end of the pipe. Discharge water should be able exit freely, with no
obstacles. Sometimes the outlet is low to the ground, and may create a pool, so the outlet is underwater. If this pool or discharge area freezes in winter, ice can block overflow and might lead to the pond flooding over.
If the spillway is a "native" stream type overflow (no pipe), make sure aquatic vegetation has not grown up in the channel and blocks overflow. Or debris tangled in the vegetation. Look for erosion damage to the channel, and repair if needed. You don't want overflow to rip out the spillway and empty the pond. This can damage the spillway, the shore/dam, and perhaps downstream areas.
If the spillway is a horizontal pipe at pond waterlevel, make sure there is no erosion around the outside of the pipe, with no debris blocking the inlet. If the pond freezes in winter, check the pipe occasionally to make sure it is not ice-blocked. (This goes for any pipe system.) Moving water will usually keep the spillway pipe ice free, but not always. (That's why road culverts can freeze in winter, requiring steam melting by the town road crew.)
Inflows should also be checked to make sure there is no erosion of earthen channels, overgrowth of vegetation, or damage or blockage to piped water feeds. Sediment pools should be monitored to make sure they are functioning.
Aeration If your pond uses aeration, there are a few options to consider for the cold months. You may shut the system down, if its primary function is to prevent algae, which will usually die down in cold weather anyway. If aeration is helpful for fish, you might want to keep it bubbling/splashing, unless the fish population has been reduced, or you cut back on feeding. Sometimes aeration time is reduced in winter, by adjusting a timer. If the aerator is located mid-pond, the bubbles or splash will usually keep an area of water ice free in cold climates. This may present a problem if the pond will be used for skating. And in winter thirsty animals looking for open water may wander onto an aerated pond and fall in. I've seen situations where a fire department rescue unit had to winch a moose out of a hole in the ice caused by aeration. One way to keep the aeration going in a relatively safe way is to relocate the diffuser/splasher near the shore, where shallow depth is not so dangerous to animals or skaters.
Fish Stocking Fall can be a good time for fish stocking. You might even score some hatchery bargains, as suppliers go into their down season. I went into detail about fall fish stocking in the September 2017 Pondology. Check this out for details.
Swim rafts and Piers These are often removed from ponds that will ice over in winter. This prevents ice damage to the structures, and makes room for skating.
Fire Protection Follow Up Eerie timing it was that just a few days after posting last month's Pondology about pond fire hydrants, the catastrophic northern California wildfires exploded. I haven't seen any specific references to ponds used for fire fighting, but I did see one story about a couple that survived by jumping in their neighbor's pool as the fires burned around them, and spending six hours in the water. I imagine a pond would have served just as well. I found another California story from one year ago about a pond that was used to supply fire fighting equipment, including helicopter water lifts. Right now we're having an extended dry spell in the east, with warnings against starting outdoor fires. West coast, east coast, and in the middle, ponds are looking better than ever for fire protection.
Topics vary from month to month and provide great information when researching where you want to build a pond, or how to keep it clean. Other areas of interest are pond use for more than swimming, and how to keep fish happy in your pond.