First-flush device

The purpose of a first-flush device or first flush diverter is to prevent the entry of debris and toxins into the storage/distribution system of a rainwater catchment system.

First flush devices on Appropedia pages

• Rainwater catchment at Isla Urbana #First Flushes
• Rainwater harvesting#First flush systems
• Old Growth Cellar rainwater catchment #First flush bucket
• Ersson rainwater harvest and purification #Roofwashers
• WaterPod FBD Rainwater Purification #Description of Final Project
• Daycare rainwater catchment system#The First Flush Sediment Trap
• And all of those linked below in the gallery.

Examples of first flush systems

• Various First Flush Systems
• 
  Rainwater catchment at Isla Urbana
  208 liter first flush with floating ball
• 
  Practical Action Rainwater Harvesting
  a) the tipping gutter first flush system and b) the floating ball first flush system.
• 
  Old Growth Cellar
  15 gallon first flush tank with side drilled.
• 
  Ersson's roofwasher
  a hollow ball which, when filled by the initial flow of water, seats itself onto a rubber gasket.
• 
  Waterpod Rainwater Filtering
  See 2) Ball Valve 3) First Flush
• 
  Parras Mexico Daycare Rainwater
  The first flush is caught by 4" pipe with a floating ball.
• 
  HSU Chiapas Rainwater
  Old design that leaked replaced by next image.
• 
  HSU Chiapas Rainwater
  New design that use two parallel lengths of pipe.
• 
  CCAT Rainwater
  First flush with clear pipe.
• 
  Zane Middle School rainwater catchment
  First flush using a small pickle barrel.
• 
  CCAT greenhouse rainwater catchment
  First flush using a long black pipe.
• 
  Loleta Elementary rainwater
  First flush using a small section in a long white PVC pipe.
• 
  Sanctuary rainwater
  First flush using a blue 20 gal barrel.
• 
  Las Malvinas rainwater 2014
  First flush using a large white pipe.

Links

• First Flush Calculations
• Saferain - Alternative to the Roof Washer