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Drainage and backflow
Water Management
Every drop has to go somewhere. Fernco drainage and backflow products move stormwater off the property, out of the basement and out to the outfall, and keep it from coming back.
Flap valves
Channel drains
Downspout connectors
Check valves
Debris traps
Featured · Stormwater outfalls
Flap Valves
Water flows out. When the water outside rises, the flap closes on its own. No power, no operator.
Corrosion-resistant HMWPE flap gates for outfalls and drainage systems where rivers, ponds and tides push back.
Tap a + to explore
Five details that set Fernco flap valves apart.
Wall mount
FV4 to FV24. Fastens to a headwall or structure with an FVMS stainless mounting set.
EPDM seal
A co-extruded EPDM seal installs clean, with no added tapes or sealants.
316 stainless
Marine-grade 316 stainless counterweight and hardware.
HMWPE flap
Won’t rust, pit or seize. Lighter than cast iron or stainless, and low scrap value helps reduce theft at open sites.
Spigot mount
FVS4 to FVS24. Connects to the pipe end with a Fernco Strong Back RC shielded coupling sized to the pipe OD.
12 sizes, wall or spigot mount
4″–24″
Exceeds the leakage-rate performance requirements of DIN 19569-4 Class 5 and BS 7775
Class 5
Marine-grade stainless hardware
316
Community flooding
When rivers and ponds rise, an outfall becomes a way in.
Municipal discharge
Keep stormwater moving the right direction.
Coastal and tidal
Seals against tidal backpressure and surge.
Follow the rain
From the roof to the outfall
One storm, four places water causes trouble, and the Fernco product for each.
01 · The roof
Downspout Connectors
Rain off the roof needs a way underground. Connect a downspout to a 3″, 4″ or 6″ drain line with no clamps or glue.
02 · The driveway
StormDrain Plus
Water pools at the garage door and across the patio. A modular channel drain catches it, rated for cars and light trucks under 20 mph when set in concrete.
03 · The basement
Sump Pump Check Valves
Groundwater fills the sump pit and the pump sends it out. A check valve keeps it from falling back in. Threaded or slip, with a quiet ProCheck model coming November 2026.
04 · The outfall
Flap Valves
City storm lines end at a creek, pond or shore. A flap valve lets the water out and keeps high water from backing up the pipe.
Do the math
How much water comes off your roof?
An inch of rain on a roof adds up fast. Most of it lands at the downspouts and runs across whatever is below them.
One inch of rain on one square foot of roof is about 0.623 gallons (USGS: 27,154 gallons per inch on an acre). Measure the roof footprint, not the shingle area. Assumes all of the rain reaches the gutters.
Water off the roof
gallons in one storm
gallons at each downspout
55-gallon drums
Water wells
Water Well Debris Traps
Below ground, loose rock and sand can fall down the gap around a well liner. A flexible shale trap blocks it before it reaches the screen and pump.
Where to next
Stock it, spec it or put it to work.
Distributors and retailers
Carry Fernco water management
Flap valves, channel drains, downspout connectors, sump pump check valves and well debris traps. A full drainage and backflow line from a supplier you already know, with Fernco reps behind it.
- Products for homeowners, contractors and municipalities
- Sell sheets, drawings and install instructions ready to share
- Fernco reps in the field to support your counter and your customers
Engineers and municipalities
Specify it
Cut sheets, drawings and submittal packs for every flap valve size and mount, plus a rep who can walk the site.
Contractors and homeowners
Buy it
Find Fernco products at plumbing supply houses and hardware stores near you.