20" DIY Cascade Falls Box [PB1762]

20" DIY Cascade Falls Box

Create a natural-looking pond-less waterfall with our 20" DIY Cascade Falls Box. This compact, one-piece molded waterfall box delivers water across a 20-inch spillway, making it a practical choice for smaller backyard waterfalls, landscape beds, and custom cascading streams.

The integrated landscape lid helps the box blend into surrounding rockwork and planting areas. Two factory-installed spinweld connections provide flexible plumbing options. This is the individual waterfall box, not a complete pond-less waterfall kit.

Our 20" DIY Cascade Box creates a defined starting point for a waterfall or stream. Water enters the molded box through the plumbing connection and flows over the front spillway into the surrounding rockwork.

The molded landscape lid provides a place to incorporate suitable gravel and plantings, helping conceal the waterfall box within the landscape.

Two factory-installed 1.5" spinweld inlets allow the installer to select the appropriate connection side. The included plug closes the unused inlet in a typical installation.

One-piece molded waterfall box

Integrated landscape lid

Two factory-installed 1.5" spinweld inlets

1.5" PVC plug

1.5" to 1" PVC male adapter

1" PVC adapter hose connector

A pump, reservoir, protective underlayment, waterproof liner, flexible plumbing hose, and decorative stone are not included with this individual Cascade Box. These items must be provided separately to create an operating pond-less waterfall.

For a coordinated package that includes the primary waterfall-system components, explore our DIY Small 20" Cascading Falls Kit .

Maximum pump flow is the Cascade Box rating, not a guarantee of delivered flow. Actual operating flow depends on the pump, elevation, plumbing, and installation.

A pond-less waterfall circulates water through a concealed underground reservoir rather than collecting it in a visible pond.

In our DIY system, a submersible pump sits inside a protective Canyon Matrix™ in the lined basin. The pump moves water through flexible PVC hose to the Cascade Box at the top of the stream.

Water exits the 20" spillway, travels over the rockwork, and returns through the gravel into the hidden reservoir. The process repeats while the pump is operating.

Our Canyon Matrix™ is designed for smaller cascading waterfall systems and provides protected pump access while maintaining water-storage space within the reservoir. It is sold separately from this Cascade Box.

View Canyon Matrix™ specifications

Choosing the correct waterfall box depends on the desired spillway width, available installation space, and required water flow. Compare our available models below.

For additional configurations, explore our Pond-less Waterfall Spillways and Cascade Boxes .

The 20" DIY Cascade Box installs at the upper end of a lined waterfall or stream. Prepare the reservoir and stream area before positioning and connecting the box.

Choose the waterfall location and layout. Confirm the reservoir size, stream path, plumbing route, and desired elevation. Contact your local utility locating service before excavation.

Excavate the reservoir and stream areas. Install protective underlayment and waterproof liner. Position the Canyon Matrix or other properly designed reservoir components according to their installation instructions.

Place the box on a solid, properly supported and level base at the top of the waterfall. Extend the liner past the Cascade Box placement area and support the surrounding sides as directed in the installation guide.

Select the appropriate inlet and connect the pump hose using compatible fittings. Close the unused inlet with the supplied plug. Verify that the pump and plumbing are properly sized for the installation.

Position rockwork near the spillway, complete the stream edges, and fill the reservoir. Start the pump and check that water travels evenly over the spillway and returns to the reservoir without escaping the lined stream.

Use the official DIY Cascade Box and Canyon Matrix Installation Guide for detailed component positioning, connections, liner placement, and excavation instructions. Actual reservoir requirements depend on the complete waterfall design.

Keep the spillway and surrounding stream free of leaves, sediment, and other debris that could redirect water outside the liner. Regularly inspect the pump, plumbing connections, and underground reservoir water level.

Water lost through evaporation and splash must be replaced to maintain adequate pump submersion. An automatic water-fill system may be considered for compatible reservoir installations.

In freezing climates, follow our seasonal maintenance instructions. Ice buildup can redirect water outside the waterfall, and improper pump winterization can cause equipment damage.

Our pond-less maintenance guide provides additional recommendations for cleaning, seasonal shutdown, and spring startup.

Access our official installation instructions, technical drawings, and maintenance information before beginning your waterfall project.

See our DIY Cascading Falls installation videos for a closer look at reservoir preparation, waterfall-box placement, plumbing, and stream construction.

These videos demonstrate the broader DIY waterfall system. The pump, liner, reservoir components, and other materials shown in a complete installation are not included with this standalone Cascade Box.

Not sure which Cascade Box, pump, or reservoir components will work best for your project? Our Sales/Tech Team can help you review your waterfall layout and equipment options.

No. This is the individual waterfall box with its integrated landscape lid and supplied PVC fittings. A pump, reservoir, liner, hose, and other installation materials must be purchased separately. For a coordinated system, consider our DIY Small 20" Cascading Falls Kit .

The maximum rated pump flow is 2,500 gallons per hour. Pump selection should also account for the waterfall's vertical rise, plumbing length, friction losses, and desired water appearance. A pump's advertised maximum flow is not necessarily the flow delivered at the waterfall.

The box has two factory-installed 1.5" spinweld inlets. Our documented fittings include a 1.5" PVC plug, a 1.5" to 1" PVC male adapter, and a 1" PVC adapter hose connector. Consult the installation guide when selecting and connecting your hose.

Yes. Our DIY Cascade Box installation guide specifically covers systems using the Canyon Matrix™. The Canyon Matrix provides protected pump access and reservoir water-storage space beneath the finished rockwork. It is sold separately from this Cascade Box.

Yes. The integrated landscape lid is intended to help the box blend into surrounding rockwork and planting areas. Our installation guide illustrates using suitable gravel and plants around the lid. Keep the installation accessible for inspection and maintenance.

This model is primarily designed for smaller pond-less waterfall installations. It should not be assumed to replace a dedicated fish-pond filtration system. For a water garden or fish pond, choose equipment with the appropriate documented filtration capacity.

In freezing climates, monitor running waterfalls for ice dams that could divert water outside the liner. If shutting down, follow our maintenance guide for pump removal, equipment cleaning, and reservoir care. Winter damage is not covered under the published warranty.

Our lifetime plastics warranty covers manufacturing defects in Blue Thumb Cascade boxes for the original purchaser, subject to the published warranty conditions. Proper installation is required, and modifications after purchase void coverage. Labor and freight are not included. Review the official warranty document for complete terms.