While listening to Paul and Kelda's podcast #112, it occured to me that a significant problem with online ponds is maybe not common knowledge. Whats an online pond you ask?
An online pond is one that IS connected to a 'natural' surface waterway (creek, stream, river etc.) , whether that waterway flows in and/or out of the pond.
An offline pond is a pond that is not directly connected to 'natural' surface waterways.
This was heavily stressed to me by one of my college professors in my aquatic ecosystems class. Offline ponds are ok, but online ponds are not. Basically the reason is that when a pond is connected to a waterway it heats up the temperature, and can change the volume of water and sediment load of that waterway, so much so that it can drastically alter the waterways ecosystem. This can be disastrous for indigenous aquatic life, as they can be extremely temperature sensetive. It can result in the extinction of some species within the region of said pond if it's big enough or designed a certain way.
So please consider this when planning/constructing ponds.
Offline ponds however, are usually alright in this respect as long as they are far enough away from existing waterways. Check with local authorities as to the safe distance, cuz I can't remember the number.
my pond is not connected to a waterway, only drainage and groundwater..but I would love to supply a flowing well inlet to it and drain the overflow into the swamp in the back that eventually drains into a river ..
right now it is only filled by snow and rainfall and groundwater..
Bloom where you are planted.
Brenda; My understanding is that if you create new 'streams/creeks/canals' properly from artificial pond to artificial pond, that this is ok. Not sure about your idea to drain into a swamp then a river though.
Fred; I had thought about beavers actually, and how they fit into this. I remember as a kid watching beavers make ponds near my grandparents cottage (and wishing I could be a beaver!) I'd have to ask my professors their opinion on this, and also the severity of any dangers online ponds may pose. I do know that my province takes this issue very seriously, and is enacting stream rehabilitation projects to correct some of the problems they cause. Online ponds are either banned or heavily restricted. I've contacted a conservation authority friend of mine to get more concrete info.
The advantage of slowing down water is that it creates an ecosystem. When I was young, the big push was to preserve wetlands, not drain them. Wetlands, by definition, slow down water. Water rushing down a waterfall does produce much of an ecosystem, though it is very pretty. (to use an extreme)
My opinion is what is needed is diversity and lots of it. If there are no wetlands, you won't have waterfowl and all the things associated with them. If all you have is still water, you may well not have trout and other species who need oxygen, etc.
Perhaps the biggest argument against online ponds, is that unless you want to be as busy as a beaver repairing it all the time, it is better to be offline. Seasonal fluctuations of water flow can be very hard on a pond.
The problem is probably placement. For example, to do as Sepp Holtzer did, which was to make a wetlands deeper is nothing more than turning back the clock of time since it originally was a pond most likely that filled in. But, to dam a fast moving stream creates something was not there, and won't be there in the future - so you have forced your will on the environment in a way that isn't very appropriate, and may well result in degradation of the system.
I have an online pond that is where two spring fed streams (originating on my property) come together in a bowl. In the past, this was just wet, not even a decent wetland and I had to build a bridge there. So, instead, I built to large ponds which are now full of life and the water is cleaner for them since I planted trees around it, and of course, the shade keeps the water cooler. And, instead of being shallow stagnant water, it is now eight feet deep, which results in cooler water, not warmer. The total cost for the system was 5,000 USD, so it will stand up to fluctuations. And yes, my ponds have tropical waterfowl, a small species of caiman, fish, etc .
So, all of that to say this, it isn't as simple as offline vs online.
Sustainable Plantations and Agroforestry in Costa Rica