Water Usage Statistics
Our goal with water usage was to use water at a fraction of a level of a traditional commercial office building. We did this in a variety of ways, from selection of efficient plumbing fixtures to reduction of use of city water through the use of cisterns. Our data is below.
- The statistics come from our monthly City of Detroit water bills.
- Unit of measure = gallons (water dept measures in cu, where 1cu = 100 cubic feet = 728 gallons)
- 'Usage Per Person' is calculated based on the number of people that are in Businesses-in-Residence at the beginning of each month, plus the number of volunteers and paid contractors that work more than 2 days a week.
Sources of Water
- Our water comes from the City of Detroit Water and Sewerage Department, which gets its water from the Detroit River and Lake Huron.
- Water for outside use comes from 2 cisterns, one on top of our roof, and one under our parking lot. Together, they collect about 2,000 gallons of water.
Uses of Water
- 4 Toilets (@ 1.28 gal/flush)
- 5 Sinks
- 3 Bathroom (0.5 gal/min + automated)
- 1 Kitchen
- 1 Mop-basin
- 2 Dishwasher (4 gal / load)
- 1 Shower (2.5 gal/min shower head)
- Coffee / Drinking
- Outdoor watering. We harvest the water that we use for outdoor watering in 2 cisterns (1,700 gallons total) and only use city water when the other water is exhausted. Our goal is to use no city water for outdoor use.
Water Usage Charts
- April 2013 showed a slight downturn in usage from 3 previous months
- Please note that in October we had a valve that didn't close on one of the toilets, causing it to run all weekend, which caused the spike in water usage. A repair was made and the problem has not recurred.
- Average 35-40 guests every Friday
- We averaged 33 gallons per person in the month of April. We have 69 people in the Green Garage.
- Studies show water usage per person per month in office space is between 300-500 gallons. sources: US Department of Energy Federal Office Building Water Efficiency Report and North Carolina Division of Water Quality
- Water usage per person decreases as number of people in building grows over time.
- In April 2013 we spent about $47 on water with a population of 69 in the building.
Past Water Usage Charts