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40-Gallon Flo Well Storm Drainage Dry Well

  • Alternative to heavy stone-filled dry wells
  • 2 ½ times more detention volume compared to gravel dry wells
  • Collects, detains, and slowly releases water out into soil
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Product Overview

The right solution for draining areas in yards prone to flooding, the Flo-Well® Dry Well System is installed underground to collect, temporarily store, and slowly release excess water into the ground. The gravel-free interior provides 250% more detention volume than comparable sized gravel dry wells. Traditionally a dry well is an underground hole filled with heavy stone and gravel. With the Flo-Well Dry Well drainage system only a small amount of gravel is needed at the base of the tank to prevent scouring, and no heavy equipment is needed to install. Water collected upstream with a catch basin or channel drain is carried by pipes into the Flo-Well Dry Well, and seeps out through the open bottom and weep holes (punched out as needed). For local areas that require stormwater detention and infiltration on property, the Flo-Well Dry Well System is an accepted product, either installed by itself or as part of a larger integrated setup. The Flo-Well Dry Well also works well with rain gardens and bioswales to manage the flow and absorption of runoff from impervious surfaces. We’re here to help! NDS offers free tools such as the Flo-Well Drainage calculator, Home Drainage Center, and NDS Stormwater Drainage mobile app to help make your project a success. The preferred choice of contractors, NDS is dedicated to helping you with the products, tools, and support you need to get the job done right the first time.
  • Protect property from water damage by collecting, detaining, and infiltrating stormwater runoff
  • Flo-Well Dry Wells are ideal for both residential and commercial locations including yards, playgrounds, golf courses, and wash-down areas
  • Connect to 4 in. Sewer and Drain Pipe through top cover knockout; 12 side-panel knockout points connect to 4 in. Sewer and Drain and Schedule 40 Pipes; knockout points stay securely in place if not needed
  • Gravel-free interior provides 250% greater water holding capacity than comparable gravel-filled dry wells
  • The Flo-Well Dry Well can be buried or stacked up to 8 ft. deep and supports pedestrian traffic including lawn tractors
  • Side panels, when assembled, form a 24 in. dia. X 24 in. tall cylinder; with addition of cover the overall height is 28-3/4 in. with 50 gallons storage capacity
  • Special ribbed design on side panels adds structural strength for long-lasting durability; no need to pack gravel inside
  • Thirty 1 in. knockout weep holes provide additional infiltration capacity, simply punch out with a firm tap using a hammer and wrap Flo-Well Dry Well with filter fabric wrap (sold separately) to prevent soil intrusion. Use a bottom panel (sold separately) to the Flo-Well Dry Well to prevent soil erosion or provide a base for a sump pump
  • The Flo-Well Dry Well System works as a stand-alone product or in conjunction with other compatible NDS products such as Catch Basin Drains, EZ Drain French Drains, and Pop-Up Drainage Emitters as part of a complete drainage system
  • Can be installed alone; when using more than one, install additional Flo-Well Dry Wells side by side, 18 in. apart; units can also be stacked up to 4 high when able to dig deep without hitting bedrock. No heavy equipment needed to install
  • Comes with 3 side panels and top cover, unassembled
  • Flo-Well Dry Well is made of high-density polyethylene (HDPE) using a combination of virgin and recycled content treated with UV inhibitors to prevent fading and cracking
  • Use with additional Flo-Well Dry Well components such as the Bottom Panel, Surface Drain Inlet with 6 in. Grate, and Filter Fabric Wrap; use additional Flo-Well Dry Well Kits to increase detention and infiltration
  • Use with a Pop-Up Drainage Emitter to discharge collected water at a point of release
  • Use with EZ Drain Gravel-Free French Drain System for additional detention and infiltration capacity, or in high groundwater situations
  • Onsite stormwater management protects the watershed downstream, and limits excess runoff which can lead to negative impacts such as erosion, pollution, and flooding
  • Founded in 1972, NDS is the preferred choice of professionals and the leader in stormwater management with proven products, tools, and support to help you get the job done right
  • Landscapes Compatibility Chart
  • California residents

Info & Guides

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Max. Compatible Pipe Size (In.)
Min. Compatible Pipe Size (In.)
Product Depth (in.)
Product Height (in.)
Product Width (in.)


Color Family
Compatible Area of Use
Driveway,Neighbor Runoff,Patio,Planter Areas,Pool Deck,Walkways,Yard
Grate Shape
Pack Size
Package Quantity
Pipe or Fitting Product Type
Product Weight (lb.)

Warranty / Certifications

Manufacturer Warranty
Limited Lifetime

Questions & Answers

Typical questions asked about products:

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Customer Reviews

  • 4.4
    out of 172 reviews
  • 91% recommend this product
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Showing 1-10 of 172 reviews
It's been about a month and it's working great. Havent had any issues
It's been about a month and it's working great. Havent had any issues
  • Verified Purchase
  • Recommended
1 person found this helpful
just installed it
Just installed this last night to help collect the rain water from my gutters. Seemed to be straight forward and easy to use. I used duct tape to hold the joins together while instlalling otherwise they would pop apart
    • Recommended
    4 people found this helpful
    Pros: -Lightweight -Customizable -Accurate product description -Simple Cons: -Additional parts...
    Pros: -Lightweight -Customizable -Accurate product description -Simple Cons: -Additional parts required as per installation -additional digging required for aggragrate and optional NDS top drain if used Recommendations: -glue pieces together after assembling -use sharp blade to remove knockouts
    • Verified Purchase
    • Recommended
    4 people found this helpful
    Great product, good directions/easy install, works like a charm!
    Flo well was easy to install with clear directions and good quality materials. Already had a couple heavy downpours and it's working like a charm. Picture taken with top off for perspective, final install will be completely covered up to overflow emitter on top.
    • DIY
    • Verified Purchase
    10 people found this helpful
    Solved my sidewalk drainage problem
    I had a drainage problem next to a paver sidewalk every spring after the snow melted and during heavy rain storms. Due to poor grading of the yard there really wasn't anywhere for the water to go. I installed this and added the top grate. We had a couple of down pours since the install and it is working great. The water no longer floods the sidewalk as the area in the yard where the water used to collect now drains properly.
    • Verified Purchase
    • Recommended
    30 people found this helpful
        It is well made, The "punch out" holes are hard...
        It is well made, The "punch out" holes are hard to punch out, so I used a drill and 1" bit. The top is a bit hard to seal shut. Like it wants to seal or snap shut but it doesn't. I kind of just sit on top of the sides. But It assembles pretty good. I used duct tape to really keep it together, you don't have too. Overall I do recommend it. It will last, the plastic is very strong.
          Excellent customer service from plumbing specialist would highly recommend the...
          Excellent customer service from plumbing specialist would highly recommend the NDS 40. Great design, ease of assembly and functionality.
            Really good quality and easy assembly but really difficult to...
            Really good quality and easy assembly but really difficult to knock out the holes.
              Showing 1-10 of 172 reviews