The Greywater Guerrillas
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Other Projects

Direct Greywater:

Branched Drain to Bamboo in Berkeley, CA.

Washing machine to large yard in Arcata, CA

Outdoor pedal-powered washer in Oakland, CA.

How to do drip irrigation with greywater.

Constructed Wetlands:

Tiered wetland -- greywater passed through three wetlands, in Austin, TX.

Small wetland to filter shower and grow cattails for use in Oakland, CA

Pretty wetland and wash water in Oakland CA

Bathtub wetlands -- to treat shower water, in Oakland, CA.

Kitchen sink water garden -- in Los Angeles, CA.

Shower water -- another shower system in Seattle, WA with a surge tank.

Composting Toilets:

The prettiest composting toilet in Oakland, CA.

Elevated indoor composting toilet in Oakland, CA

Rainwater Harvesting:

Constructed Wetland with Shower Water

Constructed 2000 in Oakland, CA

  • Goals: To investigate small-scale constructed wetlands' ability to treat household greywater for surface irrigation of vegetable crops and for use in a pond.
  • Site description: A rented house with 5 to 7 residents. Shower drainpipes were accessible in basement and were elevated 3' above garden.
  • Fixtures and output: One bath/shower, about 200 gallons a week.
  • Cost: Most of the materials were donated or gotten very cheap from salvage yards. Total cost less than $100

Water flow:

Not pictured: From bathtub, through P-trap. 30’ run
of pipe provides surge capacity so system has no
surge tank.


1. Through basement wall into infiltrator in bathtub
reedbed filled with 1/2” pea gravel, larger rocks around the inflow and outflow, and planted with
cattails. 

2. Into second gravel-filled cattail bed. 

3. Into third open-water tub with water hyacinth. 

4. Via hose to garden beds or pond. System is ele-
vated on welded steel structure so gravity can move
water

 three tiered wetland

These squash were grown with the greywater. 

squash plants
After the third tub the water is clear and odorless. It can be used for a pond, or stored for longer periods of time. cleaned greywater
  • Specifications and Notes: There is much less available irrigation water after the greywater travels through the wetland, but the water is very clean! 
  • Maintenance and trouble shooting: The original infiltrator, a 2" perforated pipe. clogged when cattail rhizomes grew into and blocked the holes. A larger infiltrator--a milk crate covered with 1/4" hardware cloth--experienced no clogging after three years. A  rush with fibrous roots invaded the system and blocked water flow through the upper tub, showing that periodic weeding is required. Cattails are cut back annually and composted