Water trim tabs

On rocks, swales, curb-cuts and dams and their effect on water flow on the land and in the air

A couple of rocks stacked together in a small row on a landscape doesn't seem like much of a big deal. But they are what Buckminister Fuller calls a trim tab action. Here's what he said “Something hit me very hard once, thinking about what one little man could do. Think of the Queen Elizabeth again: The whole ship goes by and then comes the rudder. And there’s a tiny thing on the edge of the rudder called a trim tab. It’s a miniature rudder. Just moving that little trim tab builds a low pressure that pulls the rudder around. It takes almost no effort at all. So I said that the individual can be a trim tab. Society thinks it’s going right by you, that it’s left you altogether. But if you’re doing dynamic things mentally, the fact is that you can just put your foot out like that and the whole ship of state is going to turn around. So I said, ‘Call me Trim Tab.’“

A couple of rocks can slow down rushing rainwater, and catch sediment, which then allows seeds to grow into plants, and those plants then create soil. And those plants can then further help slow down the rainwater. And as more and more plants grow they can then help evapotranspire water into the sky, to help create more rain.

So putting rocks in the landscape is a small action that can have a ripple of multiple wide effects. Its a trim tab motion.

One can see the motion of water from a dynamical systems perspective. Dynamical systems is a field of science that gives everything a position and velocity, and then sees how it evolves. At each moment in time we iterate the position and velocity forward. Chaos theory showed that in certain dynamical systems as we iterated the motion forward, small changes in initial position and velocity would get more and more magnified. The metaphoric butterfly can flap its wings in one place and affect the weather in another part of the world. In this case the analogy is you could shift the position of a rock or pebble in your landscape, and it might affect where it rains on your continent. 

Today I was playing around with placing rocks in different places in the landscape, and also thinking about what effect placing it in certain places does. Lets say you want to slow the water flow and catch sediment, do you place rocks higher up in the landscape, or do you do it further down where the water has a lot more velocity. Or do you place it halfway up the landscape to slow the velocity before it gets too fast. And what happens if you divert the water at the top of the landscape to go in a whole other direction? Where you place the rocks may cause plants to grow and then build soil there. And those plants will then also be able to stop erosion and stop the flow of water. Each rock placed affects the position and velocity of a lot of water downstream. It affects how and where water gathers. Where puddles form. Where different plants grow. And those plants then affect wind patterns, and how and when the water moves up into the sky. And the water in the sky then affects where rain occurs on the continent. So your rock placement in the landscape affects rain elsewhere.

Digging swales and ditches is also another little intervention like placing rocks. Here’s a shallow swale built on a footpath to guide the rainwater off the footpath towards the plants to help them grow.

Little rock walls and swales are something you can build in your backyard to help guide the rainfall towards helping your plants grow, and thus allowing you to save on using so much municipally pumped water to irrigate your garden.

Curb cuts are also something you can do in your neighborhood. These can allow the rainwater flowing down your street to help irrigate the roadside plants, rather than flow into drainage systems and out to sea. (For more information on curb-cuts look up the work of Brad Lancaster).

To create a larger effect on the water flow, you can organize your neighborhood into a local watershed council, and gather to create little rock walls, swales, and curb-cuts in your neighborhood.

The effect of these can add up. Water can be guided underground with these small interventions, and then come out months later in springs and in creeks. In this way creeks that normally run dry in summer can be kept running year round. This in turn can help keep the landscape hydrated. Plants may also reach their roots down into ground and reach water if the water tables are higher from these interventions. If there is normally a lot of dry wild vegetation in your area in the summer, this vegetation may become more hydrated during the hot months. This may in turn may help lessen wildfires from spreading into your neighborhood. And if you can organize these actions on a large scale amongst many neighborhoods in your bioregion it has even larger effects to protect your area from wildfires.

If you area is prone to floods, many of these small interventions upstream, little rock walls, swales, and curb cuts, along with things like rain gardens and wetlands, can prevent too much water from accumulating downstream and flooding urban areas there.

I see regenerating the landscape and the hydrological system, as a kind of engine building. In the board game world there is an idea called engine building. Monopoly is an example of an engine building game, where as you build more houses and hotels, your properties become more and more powerful. There's been a Cambrian explosion of board games in the last decade and a half, and there's many engine building games out there now like Splendor and Terraforming Mars. In Splendor you start out with some gems. With those gems you can buy development cards that then automatically give you gems. So as the game unfolds, and you have more development cards you automatically have more and more gems, with which you can then buy more and more development cards. You are uplevelling your abilities as you go.

In eco-regeneration you are engaged in engine building. You start by capturing sediment and water. With those resources you can grow plants, which then builds soil. As you get more and more soil, you up-level the ecosystem. More soil gives the ecosystem so many more options. Now many more types of plants, mycelia, microbes, animals can be on the land. 

It can take a while to build the soil though. Putting rocks in the landscape, will slowly build soil over a few years. Similarly in engine building board games, it can seem to go slowly at first. When I play Splendor, it seems hard to get enough gems to buy development cards at first. But then as the game goes on, I have more and more automatic gem generation so development cards come easier and easier.

When an ecosystem begins to have more soil and plants, more animals will come in, and those animals, especially birds, will then help spread seeds, which then causes the ecosystem to grow more ever wider across a continent.

As a chain of vegetation and forests grows from the coast to inland, something also interesting happens to the water patterns. The vegetation captures rainfall and evapotranspires the water back up , where it often blows further inland. In this way more and more rain can end up inland. Usually rainfall falls off exponentially as one goes inland. But if there is enough vegetation, the rain can continue to be come down in just as large amounts as you move further inland. [1]

As soil and vegetation build up on the land, the continent up-levels in ability, as it now has an engine that can transport more rain inland. The wind blows the water vapor inland for some distance, where it then rains, infiltrates into the ground, and is then evapotranspired back up to blow downwind to create more rain further inland. This form of transporting moisture inland is called moisture hopping, and has been studied by researchers like Van der Ent, Hubert Savenije, and Francina Dominguez [2-6]

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As I went about playing with these interventions in the flow of water on the landscape I also thought about how on a larger scale we do much larger interventions with water flow by building dams.

Dams help us with storing water from wet season to supply water in the dry season. However there are some issues with dams. Some of the most common complaints from environmentalists are that they stop the pathway of fish swimming upstream, and that it changes the temperature of the water so it is no longer as good for the river lifeforms.

There's also another issue, that is not brought up as much. And that is that it stops a lot of sediment, and that sediment is not being used to grow more plants. And those could-have-been plants are not helping to be a conveyor belt to bring rain further inland.

If we think of building an ecosystem as an engine building game, where we want to create more available soil to grow plants in, in order to uplevel, then the problem of dams trapping sediment becomes clearer. 

Soil takes time to generate and build, and after it does grow, its very important to then use it, if we want to get to the next stage of an ecosystem. 

Dams also stop rivers from overflowing into floodplains, where it can then help grow a lot more vegetation.

At first glance placing stones in the landscape seems kind of similar to large dams. Both are slowing or stopping water. Just the scale seems different at first . But on further reflection, stones are creating sediment to host plant growth and soil growth. Dams however is taking sediment out of their plant growing ability. One creates soil, the other inhibits soil creation. 

Water is a complex dynamical system, each intervention, whether its moving a rock, or creating a dam, has a multiplicity of consequences further down the chain of iteration. Its important we think about each of these iterations down the line.  

You can read past essays on this newsletter at https://climatewaterproject.substack.com

References:

1. Makarieva, A. M.and Gorshkov, V. G.: Biotic pump of atmospheric moisture as driver of the hydrological cycle on land, Hydrol. Earth Syst. Sci., 11, 1013–1033, https://doi.org/10.5194/hess-11-1013-2007, 2007

2. Van der Ent, R. J. and Savenije, H. H. G.: Length and time scales of atmospheric moisture recycling, Atmos. Chem. Phys., 11, 1853–1863, https://doi.org/10.5194/acp-11-1853-2011, 2011. https://acp.copernicus.org/articles/11/1853/2011/

3. Van der Ent, Rudi J., Hubert HG Savenije, Bettina Schaefli, and Susan C. Steele‐Dunne. "Origin and fate of atmospheric moisture over continents." Water Resources Research 46, no. 9 (2010)

4. Savenije, Hubert HG. "New definitions for moisture recycling and the relationship with land-use changes in the Sahel." Journal of Hydrology 167, no. 1-4 (1995): 57-78

5. Dominguez, F., Villegas, J. C., and Breshears, D. D. (2009), Spatial extent of the North American Monsoon: Increased cross-regional linkages via atmospheric pathways, Geophys. Res. Lett., 36, L07401, doi:10.1029/2008GL037012

6. Brubaker, K. L., Entekhabi, D., & Eagleson, P. S. (1993). Estimation of Continental Precipitation Recycling, Journal of Climate, 6(6), 1077-1089. Retrieved Feb 28, 2022, from https://journals.ametsoc.org/view/journals/clim/6/6/1520-0442_1993_006_1077_eocpr_2_0_co_2.xml