Building a pond waterfall is a great way to add beauty and interest to your backyard pond. Waterfalls can be built using a variety of materials, including concrete, stone, brick, or even plastic. The size and shape of your waterfall will depend on the size and shape of your pond, as well as the available space in your yard.
When planning your waterfall, it's important to consider the flow rate of the water. This will determine how fast the water flows over the falls and how much pump power you'll need to generate enough flow. It's also important to consider the height of the falls when planning the overall design of your waterfall. Too high or too low and the waterfall may not look natural or work properly.
Once you've determined the basic design of your waterfall, it's time to start gathering materials. For concrete waterfalls, you'll need Portland cement, sand, gravel, and water. For stone or brick waterfalls, you'll need bricks or stones (enough to build up at least 2-3 feet), mortar mix, and waterproofing sealant. If you're using plastic for your waterfall ,you'll just need enough liner material to cover the entire area where the falls will be located .
To build a concrete pond waterfall , start by excavating an area in your yard that's large enough to accommodate boththe pond  and the waterfall . Next , line  the excavation with heavy-duty plastic liner  to create a mold for  pouring  concrete . Once the liner is in place , mix together Portland cement , sand , gravel ,and water according to manufacturer's instructions . Pour this mixture into hole until it reaches desired height then let cure for several days before adding aquatic plants and fish . To build a stone or brick pond waterfall first excavate an area that is large enough for both features then line it with heavy duty plastic liner again this will act as a mold when filling with mortar mix which consists of portland cement sand limeand masonry adhesive once mixed apply liberally around stones working from bottom up letting each layer dry completely before adding next continue this process until all stones are mortared into place once satisfied with appearance use waterproofing sealer on entire structure give ample time for drying then fill hole with clean fresh water plants can go in now if desired