Atlantic SP1600 FastFalls 16" Waterfall Spillway – Pondless Waterfall Weir for DIY Backyard & Landscape Features

The Atlantic SP1600 FastFalls is a professional-grade 16” waterfall spillway built for pondless waterfalls, decorative streams, and landscape water features. Constructed from HMWPE (High Molecular Weight Polyethylene) — Atlantic’s premium impact-resistant polymer — with an internal baffle system stabilized by support cones, it handles up to 3,000 GPH and carries the weight of large decorative boulders without deforming. The innovative rear liner attachment and one-piece liner flange simplify installation and eliminate the leakage risk that comes with traditional liner-to-spillway connections. Every SP1600 includes a complete installation kit with liner flange, splash reduction foam, top grate, stainless screws, silicone, and a 1.5” MIPT fitting. Backed by Atlantic’s Lifetime Warranty. 16” Waterfall Width 3,000 GPH Max HMWPE Construction Crush-Proof 1.5” FIPT Spinweld Liner Flange Included Lifetime Warranty ♾ Lifetime Warranty: Every Atlantic FastFalls is backed by Atlantic’s exclusive Lifetime Warranty — a direct reflection of the HMWPE construction quality. No other spillway brand offers a lifetime warranty at this price point. Key Features & Benefits 💪 HMWPE — Crush-Proof Construction Built from High Molecular Weight Polyethylene — not standard HDPE — with internal baffles stabilized by support cones. Place large decorative boulders directly on the unit to camouflage it completely. The structure will not deform under rock load. 💧 Even Sheet Flow Across 16” Internal baffles calm turbulent incoming water, distributing it evenly across the full 16-inch weir width. The splash reduction foam further smooths the flow before it exits over the spillway lip, creating a clean, professional-looking sheet of water. 🔧 Rear Liner Attachment The innovative rear liner attachment and one-piece liner flange create a completely sealed interface between the spillway and pond liner — eliminating the leakage risk from settling or shifting that affects traditional side-seal designs. Compatible with 45-mil EPDM and PVC liners. 🌿 Planting-Ready Spillway Lip The reinforced raised spillway lip retains rock, gravel, mulch, and soil — and can even be planted with groundcover — allowing the FastFalls to blend seamlessly into the surrounding landscape without visible hardware. ⚡ 1.5” FIPT Spinweld Plumbing The pre-installed 1.5” FIPT spinweld fitting accepts 1.5” flex PVC hose directly, eliminating the need to source a separate bulkhead fitting. The one-piece body design eliminates any chance of leaks from seams or joints under pressure. 🏆 Contractor-Grade at DIY Price Atlantic designed the FastFalls to give homeowners access to the same contractor-grade spillway installers use on professional builds — rugged enough to handle years of outdoor exposure, rock loading, and pondless waterfall cycles. What’s Included Atlantic SP1600 16” FastFalls spillway body 1.5” FIPT spinweld bulkhead fitting (pre-installed) One-piece liner attachment flange Splash reduction foam Removable top grate Stainless screws (for liner flange attachment) Silicone sealant 1.5” slip × 1.5” MIPT fitting (accepts 1.5” flex PVC hose) Technical Specifications Specification Value SKU SP1600 Waterfall Width 16” Dimensions (W × D × H) 16½” × 9½” × 7¼” Max Pump Flow 3,000 GPH Bulkhead 1.5” FIPT — pre-installed spinweld fitting Hose Connection Accepts 1.5” flex PVC (via included 1.5” MIPT fitting) Material HMWPE (High Molecular Weight Polyethylene) Construction One-piece; internal baffles + support cones; crush-proof Liner Compatibility 45-mil EPDM and PVC pond liner Spillway Lip Reinforced raised lip — retains rock, gravel, mulch, soil; plantable Brand Atlantic Water Gardens (Atlantic-OASE) Warranty Lifetime Atlantic FastFalls Family Model SKU Width Max GPH Bulkhead Dimensions (W×D×H) FastFalls 16” ← This SP1600 16” 3,000 1.5” FIPT 16½”×9½”×7¼” FastFalls 19” SP1900 19” 4,000 2” FIPT 20½”×17”×10¼” FastFalls 26” SP2600 26” ~6,000 2” FIPT Confirm FastFalls 32” SP3200 32” ~8,000 2” FIPT Confirm All FastFalls models are constructed from HMWPE with the same baffle/support cone system, rear liner attachment, and Lifetime Warranty. Select size based on your desired waterfall width and pump GPH at your required head height. ~ = approximate; confirm larger models before ordering. 💡 Installation tip: Install the SP1600 on a firm foundation of soil or concrete block and tilt the spillway slightly forward approximately ¼”. This slight forward lean ensures water never leaks over the back of the enclosure during operation. Frequently Asked Questions How does the Atlantic SP1600 FastFalls simplify pondless waterfall installation? The SP1600 is designed as a one-piece, ready-to-plumb waterfall starting point. Three design features make installation fast: Pre-installed 1.5” FIPT spinweld bulkhead — no fitting to source; connect 1.5” flex PVC directly Rear liner attachment with one-piece liner flange — secure the liner to the included flange using the included stainless screws and silicone; eliminates liner-to-spillway leakage from settling or shifting Removable top grate — place rock and gravel on top for complete natural camouflage while maintaining easy access for cleaning Set on a firm, level foundation, connect your pump hose to the bulkhead, attach the liner, and cover with rock. The entire installation typically takes less than an hour for an experienced builder. What is the recommended GPH flow rate for the 16-inch FastFalls? The SP1600 is rated for pumps up to 3,000 GPH. Atlantic’s internal baffles and splash reduction foam are optimized to produce a smooth, even sheet of water within this flow range. For a thinner, more delicate water sheet, use a lower-output pump within your head height rating. For a fuller, bolder curtain, size toward the 3,000 GPH maximum. Exceeding 3,000 GPH risks turbulent overflow over the sides of the enclosure. For flows above 3,000 GPH or wider waterfall features, see the SP1900 (19”, 4,000 GPH max). Can the SP1600 FastFalls be used with both EPDM and PVC liners? Yes. The SP1600’s one-piece liner flange and rear liner attachment system are compatible with both 45-mil EPDM and PVC pond liners. To seal: Trim the liner to fit the rear liner attachment area Apply the included silicone sealant at the interface Secure the liner with the included stainless screws through the one-piece liner flange The rear attachment design keeps the liner-to-spillway seal on the back of the unit (inside the landscape), away from the visible waterfall face, so rock placement is unaffected by the liner hardware. How do the internal baffles improve waterfall aesthetics? Incoming pump water enters the SP1600 through the 1.5” rear bulkhead under pressure, which naturally creates turbulence. Without baffling, this would produce an irregular, bubbling waterfall with “dead spots” where water doesn’t reach the spillway edges. Atlantic’s internal baffles — stabilized by support cones — break up the incoming flow and diffuse it evenly across the full 16” width before it reaches the spillway lip. The included splash reduction foam further calms the water surface. The result is a smooth, even sheet of water across the entire weir width, with no dead spots or turbulent patches. This is the visual quality difference between a professional-grade spillway and budget alternatives. Is the Atlantic SP1600 durable enough for heavy rock camouflage? Yes — and this is one of the FastFalls’ primary design advantages. The SP1600 is constructed from HMWPE (High Molecular Weight Polyethylene), a premium polymer with significantly higher impact resistance and structural rigidity than standard HDPE. Internal support cones reinforce the baffle structure from below, distributing point loads across the full shell. Place large decorative boulders directly on top of the unit for complete camouflage. Atlantic is so confident in the structural integrity that they back every FastFalls with a Lifetime Warranty — covering the spillway body for the life of your water feature. Why Buy from Pond Pro Direct? Authentic Atlantic Water Gardens products with full Lifetime Warranty coverage Expert pump and basin sizing guidance — call or text (765) 508-4352, Mon–Fri 9am–5pm EST Free shipping on all orders Price match guarantee on identical products 30-day return period on eligible items