(888) 686-8265 Lowest Prices Best Shipping Rates

4" In-Ground First Flush Water Diverter Kit

4" In-Ground First Flush Water Diverter Kit
Images may be inaccurate. See specs table below to ensure accuracy.
Low maintenance
Easy installation – just add pipe and glue
Converts a ‘wet’ system in to a ‘dry’ system
Perfect for sloping allotments
Improves water quality, protects pumps and internal appliances



Rain Harvesting In-ground First Flush Water Diverter , part# WDIG99. Buried and out of sight, In-Ground Water Diverters are perfect for sloping allotments. On a site that provides the opportunity for the end cap of the diverter to be positioned above ground (to drain out and be accessible for maintenance), an In-Ground Diverter allows a ‘wet’ system to be converted into a ‘dry’ system.

Most systems are ‘wet’ due to the size of buildings, and the placement of tanks away from the buildings mean that there are long runs of pipe underground leading to a riser at the tank. On a sloping site this diverter ensures the diverted water and the water that would normally remain in the pipes empties out. The result – a ‘dry’ system that improves water quality.

In-Ground Water Diverter

How much water to divert

It is important to prevent heavy sediments and other roof pollutants from entering the rainwater tank/cistern. The amount of water diverted should be a minimum of 12.5 gallons per 1000 square feet of roof area (or 0.0125 gallons per square foot). In calculating the amount of water to divert, consideration can be given to (1) the surface area of the roof, and (2) the amount of pollutants on the roof and gutters.

The following factors can be used as a guide in determining the volume of water to be diverted.

First Flush Water Diverter Table

As a rule of thumb, the more water that is diverted the better the quality of water in the tank/cistern.

Multi pipe feed systems

These water diverters can handle more than one pipe

Single or multiple pipes carrying water from the roof can be directed into an In-Ground Water Diverter.

Dual Pipes Water Diverter

Installation Instructions

Determine the length of 12″ pipe required using the table.

Inlet End: The ball seat #6 is inserted into the top of the end cap as shown.

– For 3″ Schedule 40 PVC pipe infeed – insert the ball seat #6 and attach the infeed pipe hard down on top of ball seat #6.

– For 4″ Schedule 40 PVC pipe infeed – insert the ball seat #6 and glue the 3″ keeper ring (1.1″ long) hard down on top of the ball seat #6 to keep it firmly in place.

Outlet End: The outlet requires only 3″ pipe. Assemble as shown in the attached drawing making sure to insert ball #7 before attaching cap #11. Select one of the four control valves #12 and fit into hose connector #13. Save the remaining valves for possible later use.

In-Ground Water Diverter

Show More

Additional Information

Store ID X5174090
Manufacturer Info
Product Part # WDIG10
Manufacturer Rain Harvesting
Installation Instructions Rain Harvesting WDIG10 Installation Instructions
Physical Features
Weight (lbs) 4
Color Natural White
Product Type Rainwater Diverter
Shipping Info
Shipping Locations Georgia
Shipping Zip Codes 30309
live chat
find tank