Denis Hayes on the Rainwater Catchment System

Recently a reporter submitted this question about rainwater collection and use at the Bullitt Center:

I know one of the major features of the Bullitt Center is the cistern that will store all the rainwater that will then be harvested for use in the building. That’s the only water source of the Center, right? Now, is this a rarity in Seattle? I reckon in a place where there’s no so much rain, this would be more common, but I imagine that this is pretty innovative. What are the challenges in developing something like this that has made it prohibitive? Or is it fairly easy and people are just not taking the time to do more eco-conscious option available?

Denis Hayes, in his response, offered quite a bit of detail and thinking:

“First, for your general background, in most western states you actually have no ownership right to the water that falls on your roof; the “prior appropriation doctrine” requires you to let it run off to a nearby river or sink into the ground water and be used by someone downstream who has used it in the past. Until recently, in Seattle, that meant it was illegal to stop water from flowing off your roof, gushing down the street picking up complex hydrocarbons, and entering the storm sewer where it was flushed with those poisonous compounds into Puget Sound where it entered the food chain. Western water law is a mess, and many states and commissions are studying ways to amend it.”

“That said: A fair number of office buildings seeking to be “green” capture some rain water and store it for such uses as watering plants and flushing toilets. And some individual homes capture rainwater and use it for whatever they wish; individual homes are not regulated as public sources of water.”

“However, the Bullitt Center will be the first office building in the United States to capture rain water, store it and purify it, and then use it for potable drinking water. We will use rain water in our coffee, our dishwaters, our showers, and for everything else. We will filter the resulting gray water and infiltrate it into rain gardens full of vegetation in front of our building. We will make no use of Seattle public water supply.”

“All the needed technology has been available for decades, and it is commonly used in some other parts of the world. Rain water is not harvested in the US because (1) it adds a bit to the cost of a building. We have a 56,000 gallon concrete cistern in our basement, and we otherwise could have used that room for something else. (2) Public drinking water here has been abundant and safe. (3) There are legal and regulatory hurdles — in the east as well as the west — that developers would rather avoid if they can. Hurdles can slow down a project, and time is money.”

“But with climate change, rainfall patterns are changing and the snowpack, which provides most of Seattle’s water, is already diminishing. Moreover, I expect a large number of climate refugees from the dry southwest to head to Seattle over the next few decades as Arizona and its neighbors dry up.”

“The region has few, if any, new reservoirs to create to provide drinking water to the influx. To us, the best solution is to harvest the rain water that nature delivers right to our buildings. Why pump water hundreds of miles when Mother Nature delivers it to your roof for free?”

“Finally, I should note that while Seattle is truly very cloudy for much of the year, we don’t actually have much rain. We have an average of 225 cloudy days and 150 rainy days, but we receive only 37 inches of rain on average. Boston gets 43; Atlanta gets 50; Nashville gets 48; New York City 49; New Orleans 64; Houston 48. You get the idea. We hope we will be the first of thousands of cisterns built in Seattle over the next century to capture rainwater and use it for all purposes.