Introduction:You don't need a huge, spectacular goldfish/koi pond to have a gurgling waterfall; and as an added bonus a waterfall can act as a semi-natural filter My pond's a 45 gallon half barrel with a 6" waterfall.
You'll first need a pool liner designed with a lip for water to spill out of. Mine came from a big box home and garden store for under 20 bucks. You also need a submersible pump with tubing.
Set the pool liner up higher than the main pond in order for gravity to do its thing. Bricks or cinder blocks make an ideal platform. Next, organize a scavenger hunt for attractive, colorful and fairly large rocks. The beach is a great place to search. Place the rocks around the liner to anchor it into place and provide natural looking camouflage. The pump goes in the lower pond with one side of the hose and the other end in the upper pool. You'll want to camouflage the hose with plants and/or rocks as well. Make sure the upper hose is firmly in place, or you risk emptying the pond - which your fish will definitely not appreciate!
Take a field trip to the pet store to get some smaller, flat colorful rocks. Not all outdoor rocks are aquarium/pond safe- many have harmful elements which will break down in the water and become harmful to fish and other aquatitc life. Arrange in a pile under the water flow so the water cascades and hits the lower pond at different angles.
At that same pet shop, or a garden shop that includes aquatic garden supplies; pick up some marginal, or semi-aquatic plants. My crop includes cardinal flower, sagittaria, lobelia and for good measure some lucky bamboos from the local Oriental market. At the local dollar store you can get a glass bowl, some marbles and/or a couple of bags of those colored glass decorative "stones". Fill the bowl with the marbles and glass pieces and then plant your aquatic garden. Waste and sediment from the fish will get sucked up and settle in the upper pool. The aquatic plants in the upper pool will suck up a lot of that waste as nutrients. Electricity powers the whole deal, so it's not 100% green, but at least it's a hybrid!
There's nothing wrong with adding some silly extras, if that's what you're into. A fake frog and turtle sit pondside here as well as a plastic Cape Cod souvenir lifeguard gal - and at night the scene sometimes brightens with colorful LED light up plastic waterlilies and/or floating candles.
select one here...