I’m thinking of constructing a small pond with a simulated waterfall or cascade - maybe more of a large water feature than a pond - near my house in the woods. I’m surrounded by large hardwood trees. I’m worried that leaf litter will mean unending maintenance. I’d appreciate advice based on other folks’ experience.
With a black pond liner , you will not see the debris. For about 20 years I have had a small pond with a 30 ft. long small, recycle stream. I am in a forest. Once a year I would get in and clean the bottom, The last few years I could not because of a health problem. The only change I see is that the water lillies bloomed better this year although they have not had the recommended fertilizer the last few years. Apparently the pond has gone feral and the decomposing litter is fertilizing the water lillies . The Koi, tropical fish and native frogs don't seem to care. I do plan to clean it this fall................... There is a recent improvement in pond cleaning/ filtering. I did it by accident so mine is not optimum. Add a bog as the filter. So if you are thinking of a 1000 gal pond , add a 500 gallon bog. For example if you want a 10 ft long rectangular pond add a 5 ft long bog, the same depth as the pond. Build a porous wall between. I used cinder blocks and house brick ( the kind with a few round holes through them. Put a "well" at the far end of the bog, something like 12" plastic pipe with holes in it; put your pump in the bottom of the well Fill the bog with lava rock ( or equal, it take a lot). Water will pass through the holes in the cinder block and brick into the lava rock where it is filtered then goes to the pump which pumps it back to the top of your waterfall or stream. This also fixes a big problem, debris clogging up the screen of the circulation pump. I am sure you can find details in a pond magazine or website
I don't see any way to avoid maintenance with a constructed pond. You'll have to put in some effort at least twice annually. I would recommend fishing the leaves out by hand or by net as someone else suggested. If the sight doesn't bother you, you could possibly wait until the end of the season to get them all. That won't work if you plan on growing some lilies out other pond plants as that could shade them out and stunt it prevent growth. With a waterfall, I'm guessing you're planning on installing a pump, pumps do require a certain amount of maintenance on their own, but I would also hesitate to leave the leaves in the water too long in case they interfere with your pump. The other point about allowing leaves to fall to the bottom is decomposing leaves raise the biological oxygen demand. This could be fatal to fish or amphibians if you plan on having any critters in your pond.
It is possible to put in a lower maintenance pond that you could possibly let all the leaves naturally become part of the pond ecosystem, but I can't see that going well with koi fish and waterfalls if that's what you have in mind. And it might require a bit more money and work in the first year or so.