Compared to our modern irrigation techniques, ancient water harvesting and
distribution practices required less resources (were less expensive), were
permanent (a modern system is temporary compared to earthworks), did not
increase salinity, recharged aquifers instead of depleting them and kept water
The old styles were not without their own problems. Erosion, has been and still
is enemy number one to any land developer. Proper planning should be able to
route erosion before it gets started. An ounce of planning, is worth a pound of
plodding. It is interesting to note that even these ancient techniques were
copies. They mimic natural patterns where water pools and evaporation is
Before the advent of irrigation, the people of the SW USA had utilized numerous
techniques to harvest rainwater. Cliff-base plantings took advantage of the
naturally concentrated water at the base of cliffs. Mimicking this concept, the
idea of water harvesting with basic check dams and basins holding up seasonal
rains came about. Archaeological evidence of these check dams can be seen
throughout modern day CO, UT, NM, Mesa Verde, Hovenweep National Park, upper
Rio Grande, Chama drainage, Pajarito plateau.
The people that lived on the land for millennium probably had some intimate
knowledge of the land. Techniques developed by these cultures of the past can
prove as valuable reference points for anyone wanting to understand and
intervene in something as complex as an ecosystem. We should try to learn from
historical failures as much as successes.
Mulching is one of the easies things that can be done to prevent evaporation.
While there is not much detritus matter in the desert, there are plenty of
rocks. Gravel mulch was utilized by the Hohokam, Mogollon and Anasazi in the
same way we spread our wood chips today.
The techniques continued to evolve into waffle and grid gardens. Waffle
gardening works similarly to modern imprinting by holding water in sunken beds
with a small rock-wall edge. These were located near villages and functioned as
a kitchen garden for the three sisters: corn, beans, and squash. Grid gardening
is a larger scale version, linking several waffle-style gardens together into a
net-and-pan like system. These systems were heavily utilized by the Zuni tribe
of the Pueblo people. There is a tradition of hand-crafting the smaller 60cm
(2') waffles that has been passed down for generations. Alternatively there are
many sites that exhibit a larger 3.3m (10') grids that are usually more crudely
crafted, as with a stick.
These grid/waffle gardens are quite expansive, often covering several square
kilometers. Was it an ineffective cropping strategy and they needed large
swaths of land to get a little harvest or was their society that large?
Really Ancient Techniques: Savory's Stuff
In modern times we are lead to believe that reducing the number of grazing
animals and resting the land is the go-to solution for degraded lands. Allan
Savory has shown that by increasing stock in a way that mimics large, ancient,
mega-herds, the land will recover faster than when left to rest.
When resting grassland, the grass builds up, but does not decompose. This
smothers future grass in a process known as oxidation and allows woody
vegetation a foothold. The solution of burning the grass leaves the land bare
and nutrient-less again.
Huge herds (~400% increase from modern rates) of ancient animals eat the tall
grass, defecating as they graze, and trample last season's dead grass, mixing
their feces and dry grass season after season. This mulches the surface with a
reasonable mix of carbon and nitrogen, catalyzes decay and fertilization. The
animals' hoofs even help by acting as micro-imprints, holding more water in the
The key to success is mimic the herd's natural tendency to stay close together
and move frequently. In a managed system you will move the animals every few
days between small subsections of the land.
This technique is working today on 15 million hectares spanning 5 continents.
Depending on initial conditions, for the first year or two, extra feed may be
required. Once vegetation recovers, usually within 1 year, the system can be
managed sustainably with a positive feedback loop putting fertility into the
More recently, in the late 1800s and early 1900s, the railroad followed the
American pioneers west. Communities sprang up along the tracks in places like
Albuquerque, El Paso, Etc. Many "greening the desert" engineering projects were
undertaken over several decades. One early attempt involved copying the
indigenous' woven dams to irrigate from watercourses. The engineers used woven
baskets filled with rocks on a larger scale than the natives. It worked until
one of the seasonal flash floods. The natives' woven dams broke, acting as a
blow-off valve and preventing the flooding of their settlement; the engineered
baskets stood strong and the town was badly damaged in the flood. Another
attempt involved a complicated dam with adjustable spillways etc. This
also collapsed during a flash flood. In both events, people lost their lives.
In the Jornada region an agricultural center has been in operation since 1912
with 192,000 acres and has been expanded several times over the last century.
During the early 1900's, and several times since, series of swales were
installed. Some were "gone" by 1970, but others were still aerially visible as
late as 1996. For almost a hundred years there has been no maintenance done.
Simple solutions are often more effective than the failed irrigation
engineering feats of the same era.
Seasonal flash flood rain events are common to many deserts. The Chihuahuan
desert is no exception. The roads that pierce into the deserts of the
southwestern USA have caused problems from day one. The rains are concentrated
by the culverts and the resulting hydraulic pressure creates a jet of water
that causes massive erosion. Large swales were installed in the 1930's along
the highways in places like Arizona. These swales hold up the water, soaking it
in slowly, rather than passing it under the road. This water then fuels growth
along the roads that stops the erosion, lowers the albedo and temperature of
the vegetated earth, and reduces wind damage to the road. These, like the
swales in Jornada are a standing testament to the effectiveness of simplicity.
Catching Water in A Dust Bowl
During the 1930's Dust Bowl, scientists were working to understand what could
be done to stop the devastation. One solution was to plant Maclura pomifera
(osage orange/monkeyball) in huge rows to slow winds, and stifle erosion. M.
pomifera has many other benefits as well, fulfilling permaculture's
multi-functional criteria. As a living fence it was the original barbed wire
and it is one of the highest BTU woods available. A truly superb organism.
Though it was a drought, there was actually some rain during the dustbowl, the
real problem was that the soil was bare and dried out so the water wouldn't
soak in before it drained away. Howard Finnel from Texas A&M figured this out
and developed a furrowing system that was done "on contour". This held the
water on the land, giving it a chance to soak in.
Over a decade later, in the 1940s, Australian P.A. Yeomans developed what he
called the Keyline system. This was a great advancement beyond Finnel's swale
as the Keyline plow, a modified ripper, could be used to mechanically treat
soil very quickly. The principles of both methods are the same, use on
contour/level furrows that hold the water on the land. The Keyline ripping also
increases oxygenation deeper in the soil.
One of the founders of Permaculture, Bill Mollison, was influenced by Yeoman
and subsequently all of the many permaculturists, like Brad Landcaster, running
around today are still evolving water harvesting techniques that are a century
old in our modern history and likely far older.