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20" DIY Cascade Falls Box

SKU:
PB1762
$149.99
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Made in the USA
Maximum pump flow: 2,500 GPH
Waterfall width: 20" spillway
Dimensions: 20"W x 8.5"D x 7"H
Inlets: Two 1.5" spinweld connections
Includes: Integrated landscape lid and PVC fittings
Warranty: Lifetime plastics warranty on Cascade Box
Current Stock:
Blue Thumb | Pond-less Waterfall Components

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.

Spillway Width 20 inches
Maximum Pump Flow 2,500 GPH
Overall Dimensions 20" × 8.5" × 7"
Cascade Box Warranty Lifetime

Designed for Compact Pond-less Waterfalls

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.

Integrated Landscape Lid

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

Flexible Plumbing Connections

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.

What's Included

20" DIY Cascade Box

  • One-piece molded waterfall box
  • Integrated landscape lid
  • Two factory-installed 1.5" spinweld inlets

Included PVC Fittings

  • 1.5" PVC plug
  • 1.5" to 1" PVC male adapter
  • 1" PVC adapter hose connector
Important: This is not a complete waterfall kit.

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 .

Technical Specifications

Product: 20" DIY Cascade Falls Box
SKU: PB1762
Spillway width: 20 inches
Maximum pump flow: 2,500 GPH
Overall width: 20 inches
Overall depth: 8.5 inches
Overall height: 7 inches
Inlet connections: Two 1.5" spinwelds
Construction: One-piece molded LLDPE plastic
Landscape lid: Integrated
Primary application: Pond-less waterfalls and streams
Warranty: Lifetime plastics warranty

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.

How a Pond-less Waterfall Works

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.

Planning your reservoir?

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

Compare Cascade Boxes & Spillways

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

Specification Mini 10" DIY 20"
This Model
Corner 12" Elite Spillway 28" Small Elite 14" Medium Elite 22" Large Elite 30" XL Elite 40" Elite Spillway 16"
Item Number PB1359 PB1762 PB1861 PB2866 PB1106 PB1113 PB1120 PB1182 PB16ES
Spillway Width 10" 20" 12" 28" 14" 22" 30" 40" 16"
Dimensions
W × D × H
10" × 8.5" × 8" 20" × 8.5" × 7" 12" × 12" × 10" 32.25" × 15.5" × 5" 24" × 19" × 14.25" 33" × 20" × 14.25" 41" × 20" × 14.25" 51" × 19.5" × 14.25" 20.25" × 15.5" × 5"
Max Flow 1,800 GPH 2,500 GPH 2,500 GPH 7,800 GPH 2,500 GPH 5,500 GPH 7,500 GPH 10,000 GPH 4,500 GPH
Inlet Size 2 × 1" 2 × 1.5" 2 × 1.5" 2" 2 × 2" 2 × 2" 2 × 3" 2 × 3" 2"
Mini 10" DIY Cascade Box
SKU: PB1359
Spillway: 10"
Dimensions: 10" × 8.5" × 8"
Max flow: 1,800 GPH
Inlets: 2 × 1"
20" DIY Cascade Box — This Model
SKU: PB1762
Spillway: 20"
Dimensions: 20" × 8.5" × 7"
Max flow: 2,500 GPH
Inlets: 2 × 1.5"
DIY Corner Falls 12"
SKU: PB1861
Spillway: 12"
Dimensions: 12" × 12" × 10"
Max flow: 2,500 GPH
Inlets: 2 × 1.5"
Elite Spillway 28"
SKU: PB2866
Spillway: 28"
Dimensions: 32.25" × 15.5" × 5"
Max flow: 7,800 GPH
Inlets: 2"
Small 14" Elite Cascade
SKU: PB1106
Spillway: 14"
Dimensions: 24" × 19" × 14.25"
Max flow: 2,500 GPH
Inlets: 2 × 2"
Medium 22" Elite Cascade
SKU: PB1113
Spillway: 22"
Dimensions: 33" × 20" × 14.25"
Max flow: 5,500 GPH
Inlets: 2 × 2"
Large 30" Elite Cascade
SKU: PB1120
Spillway: 30"
Dimensions: 41" × 20" × 14.25"
Max flow: 7,500 GPH
Inlets: 2 × 3"
Extra Large 40" Elite Cascade
SKU: PB1182
Spillway: 40"
Dimensions: 51" × 19.5" × 14.25"
Max flow: 10,000 GPH
Inlets: 2 × 3"
Elite Spillway 16"
SKU: PB16ES
Spillway: 16"
Dimensions: 20.25" × 15.5" × 5"
Max flow: 4,500 GPH
Inlets: 2"

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

Installation Overview

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.

1

Plan the Waterfall

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.

2

Prepare the Basin and Liner

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.

3

Position the Cascade Box

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.

4

Connect the Plumbing

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.

5

Finish and Test the Waterfall

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.

Installation guidance:

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.

Maintenance & Seasonal Care

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.

Product Resources

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

Installation Videos

DIY Cascading Falls Installation Series

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.

View the Four-Part DIY Cascading Falls Installation Series

Need Help Planning Your Waterfall?

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.

Frequently Asked Questions
Does the 20" DIY Cascade Box include a pump and reservoir?

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 .

What pump flow can this Cascade Box handle?

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.

What size plumbing connections does it have?

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.

Can I use this box with the Canyon Matrix?

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.

Can the landscape lid be concealed with plants?

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.

Can I use this as a fish-pond filtration waterfall?

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.

What maintenance is needed during winter?

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.

What does the lifetime warranty cover?

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.