View Full Version : NDS Flo-well

07-21-2008, 12:07 PM
Does anyone have any experience with using one? How much free draining gravel underneath is required.....I have a downspout that drains on a paver walkway (need to change)....I would like to run some SCH 40 underneath and into a catch basin or a Flo-Well system... I have small island of mulch 8x10 with a Lilac tree in the middle (surronded with pavers on 3 sides and driveway on other) where I could incorporate the basin

07-22-2008, 12:14 AM
We've used them on several occasions and they work well. I think the directions state a recommended amount of gravel. We just dig the biggest and deepest hole that space and equipment will allow and set the flow-well. Gravel's cheap and is really part of the designed operation of the system, the more you have under and around, the easier for the water to leach back into the ground and the higher capacity the system will have. One thing we do and I'm not sure if it states in the instructions we line the hole with filter fabric so dirt and soil won't contaminate/plug up the gravel.

Dreams To Designs
07-22-2008, 07:11 AM
We have had great success using Flo-wells. The use or amount of gravel will be determined by the infiltration rate of the soil. If the soil allows water in very quickly, like sandy soil, you may not need any or much clean stone, if it is slow draining like clay, a larger gravel area will be necessary to hold the water from the downspout. NDS also has a simple slide rule type drainage calculator available that will help you determine what products you need and how to set them up. They also have a great support staff that can assist you. Check with your dealer, but they should have the filter fabric made especially for the Flo-well, but you may want to add an additional piece on the bottom. When we use them, we always add a top drain to the Flo-well which can be used as an inspection port along with a surface drain. If the gutters don't have some sort of leaf guard or gutter helmet, it is recommended you use a basin drain box at the entry port of the downspout to eliminate and foreign matter, like leaves or sticks from entering the drain pipe and creating a clog at the first 90 degree elbow. This is a step that is often overlooked due to cost or not knowing any better, but can eliminate the failure of your drain system.


07-22-2008, 11:35 AM
Does anyone know if they accept 6'' SDR 35......Also do any of the NDS calculators have one that can measure run-off for roofs. Have 2 downspots going into 1 pipe and would like to know whether 2 FLO-Well systems would be neccessary

Dreams To Designs
07-23-2008, 06:49 AM
Yes, that's what the calculator does. They may have a version on their web site. I believe the punchouts are for 4" pipe, but that is all I have ever used with them. If you need the volume a 6" pipe can handle, I would imagine you will need multiple Flo-wells at least.




07-23-2008, 06:50 PM
use schedule 20 it is 1/6 the cost and no difference for this application on performance.

10-04-2008, 12:32 PM
does the flow-well need a bottom? The box I bought doesn't come with one. If not, will the soil underneath eventually fill in and clog the well?

Dreams To Designs
10-05-2008, 07:19 AM
The Flo-Well does not need a bottom, unless you choose to make it a reservoir. When installing a Flo-Well, putting it on a base and surrounding with 3/4" clean stone will give you the best result. Also using the fabric separator around the Flo-Well will help keep the dirt out and assist in infiltration into the surrounding soil.

Check the PDF about the Flo-Well on the NDS Pro website and it will give you images, and information about the best installation method for a Flo-Well.

You can also get a free soil profile by looking online at the USDA soil survey maps. Thse can give you an idea of the type of soil and the depth of the water table in the areas you are working.


10-05-2008, 12:28 PM
Thanks-what kind of base are you refering to? I looked at the drawings they provided and it just looks like they placed it in the hole (bottomless).

Dreams To Designs
10-06-2008, 09:32 AM
A base of 3/4" clean stone. The more stone at the base the larger your reservoir capacity and the quicker the water can flow into the surrounding soil. It is very important you reach a more permeable layer of soil for a Flo-well to work best. I was speaking with an NDS representative yesterday at the ASLA expo in Philadelphia and he explained they do not recommend and fabric at the bottom of the Flo-Well as it would restrict the flow of water into the soil, but do recommend using the wrap around the sides of the unit to minimize soil infiltration.