Radical hydrology

09/01/2021

The plight of the least among us becomes more evident in a drought. There are those who say indoor plumbing is the hallmark of civilization, yet coho salmon might call our plumbing habits uncivilized. And not only the coho but the myriad denizens of the riparian forests and coastal flora and fauna downstream of our dams and pipelines. They, too, yearn for freshwater and in the same volumes their ancestors enjoyed for millennia.

Let us be more civil. Let us drink, wash, flush and bathe more efficiently, and more importantly, more effectively. Efficiency gives us a less-bad impact, but effectiveness gives us a more-good impact, or in the parlance of environmental politics, it mitigates the impact. 

To be effective members of a functional hydrology, let us acknowledge that we in California are national leaders in wetland loss, second only to Ohio. In an arid climate, wetlands are where the thirsty go to spend the dry season, so this loss represents a fantastic calamity for most of our friends in the non-human world. 

The riparian forest downstream of our tap in Bolinas is a wetland. The perennial groundwater flowing into the brackish ecosystem where Arroyo Honda Creek meets the sea comes from wetlands. The deep pools in our creeks where fish can over-summer are fed by groundwater flow from wetlands. Wetlands, wetlands, wetlands. This applies to every watershed in Marin County. 

We can’t stop diverting creek water or groundwater entirely, but we can mitigate our impact by building wetlands in our gardens. These can come in many forms: a rain garden planted with perennial natives, a vernal pool planted with wildflowers or a swale planted with fruit trees, flowers and vegetables. The magic is in the shaping of the earth, the “terra-forming.” Most of the hundreds of thousands of gallons flowing off our homes and landscapes in a storm event can be harvested in these earthworks. Rain tanks represent a mere drop in the bucket of potentially harvestable stormwater. 

Effectiveness metrics are not exclusive of efficiency. In most gardens I’ve seen, only a tiny fraction of irrigation water ends up in the leaf tissue of our planted plants: most of it is lost to evapo-transpiration. Either uncovered mineral earth gets sunbaked and soil moisture wafts into the atmosphere or a sea of non-native annual grasses dries up surface water (perennials sip, annuals gulp). It’s not a stretch to say that basic regenerative practices like building living soil, deep mulching and perennial cover-cropping can eliminate 90 percent of irrigation demand— not including the thousands of gallons lost every time there’s a blowout in an irrigation line.

In the paradigm-shifting words of water wizard Brock Dolman, we are leaving the drain age and entering the retain age. This is as true for rainwater as it is for sanitation. There is nary a decent excuse to not sub-surface our discharge bathing and laundry greywater into a terra-formed network of basins that effectively turn our seasonally dry raingardens into perennially moist raingardens. Install urinals connected to the greywater plumbing and you’ve just exponentialized photosynthetic capacity—in other words, lushness derived from the wholesome nutrients in pee “fertigating” (fertilizing plus irrigating) your garden. Add a grease trap and compost filter to your kitchen drain and it’s ready for the
garden. 

What’s left? One poop-flush per person per day if everyone’s regular. A massive septic tank and leach field (or a water- and nutrient-squandering sand mound) quickly become obsolete in this new paradigm. A flush or dry compost toilet and a micro-septic is the frosting on your cake. 

Of course, if you are already invested in a septic tank, you can retrofit it. Several companies make products like the Sludgehammer that treat the wastewater right in the tank and then feed into a sub-surface drip irrigation, all code-approved. 

“Anadromous nutrient pump” is the scientific name for eagles, bears, coyotes, foxes, mustelids and invertebrates feasting on the carcasses of salmon returning a veritable cornucopia of seaborn minerals deep into the recesses of their natal streams. The banqueted feasters will gorge on a winter's worth of fat and proceed to amble far across the watershed and deposit massive nutrient-rich coprolites; from that soil, blackberries, thimbleberries, hazels, bay, laurel, oaks and all the plants that make pollen, nectar and fruit eagerly await their own feast. In coastal California this nutrient pump is more than 99 percent decimated. In the retain age, we begin to reverse this trend. 

So there you go: A tried-and-true framework for mitigating our obsolete plumbing and drainage legacy. Not only could our upstream and downstream ecosystems recover their historical abundance, but our yards would come to life with unprecedented vitality and resilience. Twice the performance for half the water. Oh, and by the way, in a wildfire scenario, wetlands are among the safest places to be: They don’t really burn, and they calm fire down. Fire hates water. Mini wikoni: Water is life.

 

Nik Bertulis is an ecologist, a water systems designer and a board member of the Watershed Alliance of Marin. He lives in Bolinas.