Roly-Polys are our friends: Kowsar floodwater spreading experimental station (Southeast Iran, part 1)

On the Gareh Bygone Plain in Eastern Iran, there’s hardly any rivers that flow. A few springs make water so saline they could be used to grow saltwater fish. On occasion, intense rain falls and torrents of water come raging through the normally dry riverbeds. The floods used to race on to a salt waste downstream where it eventually evaporated. Now the floods are redirected into a set of stair-step terraces so they have a better chance of infiltrating down into the groundwater. This simple method of “artificial recharge” is effective at capturing about 70% of the floodwater and putting it underground. It also creates an oasis of plants and wildlife and costs a fraction of other technologies like desalinization or reservoirs. I visited the Kowsar Floodwater Experimental Research Station with research scientist Mojtaba Pakparvar to see what it was about.

Location of the experimental station (blue marker)

The Gareh Bygone Plain. Experimental station shown as the blue marker. On Google Maps, you can’t get there from here because there are no roads (…there are roads, they’re just dirt) The green blotches to the upper right are irrigated fields of wheat, among other crops. 

The headquarters of the station is a tidy two story building with a kitchen and bedrooms for visiting researchers and guests. 

The first stop in the morning was a room with 3-D scale models of the research station and the surrounding mountains. 

A scale model demonstrating a river being diverted into the fields.

Here’s the basic principles: floods move quickly through river channels (shown on the right in the above picture). In this project, the river is diverted into a series of terraces (left) with perfectly horizontal edges. Each of these pools is like a hydrologic speed bump, slowing the water down and giving it more of a chance to soak into the ground. Often times the floods don’t reach all the way to the bottom terrace because the water is being absorbed along the way. Any leftover water rejoins the river at the outlet of the last terrace.

As environmental as they might be, many of the people I’ve met that work in water describe their jobs as being like fighting in a war with nature, engaging in hand-to-hand combat with the elements. Many of the terms are the same, e.g. when the river is routed (redirected), the army is routed (defeated).

So if you consider floods a menace, think of these terraces as being like a series of barricades and trenches that the enemy has to fight through, being met with heavy resistance at each line. By the bottom, the invading force has suffered such attrition and losses that only scattered remnant forces can regroup with the main column.

A photo I took from an airplane from Shiraz to Tehran of another floodwater spreading site. Notice how the terraces at the top are different from those at the bottom. The top terraces get the flood first and the rest get the leftovers.

The key challenge is making sure there’s no weaknesses anywhere along the trenches, else the enemy will slip through. Maintaining an effective floodwater spreading program requires constant vigilance, checking to make sure that the bottom lip of each terrace is completely perfectly exactly level. Nature will always test and probe the defenses, and if it has any chance to erode its way through to some new path of least resistance, the water will go pouring over the wall. The point of the project is to make the water go through the path of most resistance to slow it down and keep it contained in the ponds.

A different set of terraces, taken from the plane window.

The landscape around the experimental station

Next, we drove out into the field. This area gets about 10 inches (250 mm) of precipitation a year, about the same as Albuquerque New Mexico. The evaporation potential, however, is almost as much as Death Valley. Anyone with a swimming pool would lose about ten and a half feet (3200 mm) of water to evaporation, in a typical year.  

Mostly it was bare dirt

Yet, steps away from a barren rocky desert, the demonstration plots at the station are overflowing with life. The breeze makes the eucalyptus trees’ leaves flutter and the tall grasses sway.

Eucalyptus forest on one of the terraces

We heard birds and saw grasshoppers. Wildflowers and fresh mushrooms broke through the cracks in the mud.

Wildflowers…

Mushrooms…

The night before we had been warned that it was not safe to go out after dark because of attacks by wild pigs. There have been sightings of rabbits, foxes, jackals, wolves and even gazelles. Why were they here? Because there was water. 

Caterpillar

Really furry caterpillar among the eucalyptus leaves

I found a strange black insect, armored like an armadillo. When I asked what it was, Mojtaba said “Oh, these are our friends”. It was a roly-poly (aka sowbug). These insects, along with the plants and cracks in the mud, help the water infiltrate more quickly into the soil. “Someone is getting a PhD studying roly-polys” (no joke…his name is Gholamreza Rahbar).

Roly poly bug in lower right.

The bugs were digging complicated lattices of pathways, burrowing through the hard surface crust down to about half a meter. Water can seep through the soil but it surges through these tunnels, more than quadrupling infiltration rates in the case of roly-polys at the research station. In other words, the water came, the plants thrived, the bugs came and then the bugs dug holes that now help the water go four times faster into the ground. All these dramatic changes happened in only a couple of years after returning water to the desert.  

Roly-poly hole among the gum nuts.

The trees also create tunnels flow but on a much finer scale. They grow roots that eventually die, rot away and leave tiny empty passageways underground.

Surely there must be some downside to all this, some overhead. It’s nice and all creating an oasis in the middle of nowhere for plants and wildlife to thrive. But the main objective is to get the flood water deep into the ground so people can use it later. How much water were the plants using?

That’s a good question, as it turns out….

[Continued part 2]

Pringles in the Mist (Gorillas in Rwanda)

[We’re taking a break from writing about Iran (which was in February), to take a quick jump ahead to Rwanda (where we were in late March). This is to celebrate our successful arrival in France (today!) where we’ll be for the next three months. We’ll continue our stories from Iran tomorrow. In the meantime, enjoy! Tom]

Recently we made a parody of the TV show “Stormchasers”, telling our story as amateur spotters of streamgages. Here is a follow up, using the style of Discovery Channel’s documentary show “Everest: Beyond the Limit” to describe our encounter with the Mountain Gorillas of Rwanda.

Advertisement for the “Everest: Beyond the Limit” series

As some background, Everest follows a set of mountain climbers at they attempt to reach the summit of the highest peak in the world. The trek is physically and mentally demanding as the climbers are pushed to and beyond their limits. Many of the people on the show don’t make it to the top and have to turn back early (with no refund on what is typically an $100,000 per person investment).

The early season shows are full of big personalities and the camps surge with testosterone. Each person is climbing for a mission, such as to be the first asthmatic to summit without supplemental oxygen and the first double amputee to climb on two mechanical legs. This makes turning back all the more difficult. A brash motorcyclist with bones full of metal pins fights with his expedition leader about what he can and can’t realistically achieve. He even breaks his hand on the way up and doesn’t tell anyone because he has “summit fever” and is desperate to get to the top.

Note: On reading this post, Kitty said that there’s no tie in with river forecasting here. “We don’t want this to just become a travel blog”. So… As a forecaster, what I enjoyed about Discovery’s Everest is the working through making critical decisions in the face of uncertain and incomplete information. Like forecasters, the expedition leader has to combine (and question) data that is quantitative (e.g. weather forecasts, rates that people are consuming their supplemental oxygen) and qualitative (e.g.personalities within the teams, guessing what the other teams are going to do). He uses a mix of experience and intuition, but has to make a convincing case to his team members in plain language. When someone says to a leader “Are you sure? I’m trusting you.” are they really trusting?

So here is our journey to the Mountain Gorillas written in the voice of “Everest”

Baby gorilla and park ranger taking a rest between shoots

ANNOUNCER: Today six strangers are going to risk it all to penetrate into the wild forests of Rwanda to see some of the most majestic creatures alive. Driven to the brink of extinction, there are only 790 Mountain Gorillas left in the world. Today this expedition will hike hours through the thickets of Volcanoes National Park to get a rare glimpse at some of the last Great Apes. Only a few dozen people a day are allowed to go on this journey, divided into sets of small teams. 

Location of the Volcano Park

ANNOUNCER: This team of six trekkers turned to Clanci Ferguson of Australia to be their team leader. Renowned for her safety and discipline, her followers call her “Queen of the Mountain”… but Clanci knows better.

Spirits are high as Kitty Martz and Clanci Ferguson start the day at base camp.

CLANCI: I’m not queen or king on this mountain. Listen mate, no one’s king here. We’re just mere mortals. The only king on this mountain is the gorilla. 

TOM: Clanci’s a hard driver, but she’s earned the respect of the team. We may not always agree with her, but we all want the same thing, to get in there, see those gorillas and come back alive.

Team member Tom Pagano

ANNOUNCER: Each of these trekkers has a story. Tom Pagano (according to adventurer Kitty Martz) is attempting to be the first height-challenged and bald hydrologist to see the gorillas without the assistance of a toupee.

KITTY: Tom is a driven man with lots of guts, but no hair. His head looks like an orange. I’m worried the gorillas are going to try and peel him.

TOM: I didn’t get much sleep last night, so I’m feeling kind of jittery. It’s such a rush being up here, I think I’m just surviving on adrenaline. It’s amazing that we get to follow in the footsteps of pioneering gorilla researcher Dian Fossey. It’s just like the “Gorillas In The Mist” movie.  

ANNOUNCER: Kitty Martz is a recovering snack-aholic, at one time requiring a near-constant supply of soda pop, licorice whips and salted crisps. (Kitty plays to the camera, beating her chest and scratching her head)

Kitty at the base of the Volcano.

CLANCI: I have my concerns about Kitty. She needs to bring her A-game to make it on this expedition. Not everybody has it in them. Occasionally we get people that are out of shape or come with the wrong equipment. But I’ve never seen someone put their hiking boots on the wrong feet.

KITTY (combatively): What? Cut me some slack. They’re new!

ANNOUNCER: The morning starts with a ceremony to allow the climbers to pay their respects to the spirits of the mountain.

Traditional dancing at base camp

Kitty pays her respects in her own way, demonstrating a native dance from her home country.

CLANCI: Gather ‘round and listen up everybody… We are going to hike through these fields until we reach the point of penetration. Then we will enter the jungle and begin our vertical climb towards the gorilla habitat…. We do not have an appointment with our gorilla group, it could take us five minutes or five hours to find them. But once we do find them, the countdown starts. Then will leave all equipment behind and enter “The Gorilla Zone”.

CLANCI: We will only have one hour in “The Zone.” All team members must leave the gorillas at the end of the hour. You cannot go any closer than twenty feet (7 m) from the gorillas. If a gorilla approaches you, remain still and do not make any aggressive or sudden moves. Most importantly, you must not bring any human food near the gorillas. People food is very bad for them. Also, we don’t want them associating us with food, else they’ll attack future visitors thinking they can get something to eat. (Levels gaze at Kitty). No exceptions. These rules are for your safety and the safety of the gorillas.

KITTY: (Brushes crumbs off her vest and looks around innocently) Hmmn, what’s this now?

“Why is everyone looking at me?”

CLANCI: Remember, we are dealing with a force that is outside the normal realm of human experience. Trust me, I’ve been there, I’ve seen the worst of it. I’ve seen…. things… Trust me, mates, this mountain is not to be messed with.     

ANNOUNCER: Fifteen minutes into the expedition, the exertion of walking is taking a heavy toll on some members.

KITTY (panting and sweating): This is really grueling. Just sitting up leaves one exhausted.

Kitty hydrates with a Red Bull and an extra packet of Kool-Aid.

CLANCI: (confidentially, in a hushed tone) We assessed the teams that were going up on the mountain today and ranked them from “fit” to “fat”. We sent the fittest group after the most remote family of gorillas. That should give them a good workout for a couple hours.

FIT TEAM MEMBER: (Exasperated at having to return to base camp first, long before the other teams): Frig!!! (Fit team saw their gorilla group after ten minutes walking and so had to return early – true story).

CLANCI: This other group here will visit the “Umubano group”. This is a group we usually only reserve for school children or visiting heads of state that are pressed for time.

Clanci, Kitty and Tom work their way through the jungle

ANNOUNCER: However, late into the morning, things aren’t going to plan. After a draining two hours of walking, Clanci’s group comes to a technical point in the climb. At the infamous “First Step”, the path narrows down to a bottleneck and the climbers have to ascend in a single file. Progress is slow…. Up ahead, a group of Icelanders is causing a traffic jam. 

Icelander Kristbjörg Una Guðmundsdóttir reaches the top
with the assistance of the park rangers. “Þetta er mjög þreytandi” she exclaims.

Tempers flare at the base of the First Step.

KITTY: Oh c’mon! Seriously? People that have no idea what they’re doing have no business being on the mountain. (Shouting) Let’s go already! Let’s get a move-on.  

TOM: When you’re out here, you just want to go go go. It’s immensely frustrating having to sit here and wait when you know that you’re so close to the top.

ANNOUNCER: Without warning, excited chatter on the radio raises the spirits of Clanci’s expedition. An advance scout has spotted broken branches and flattened grass, evidence that the gorillas might be near.

CLANCI: Right team, you know the drill. We are at the gateway to “The Gorilla Zone”. Our hour starts now. We drop our packs here and come back for them later.

(Team members put stacks of gear into a large pile… A bulge inside Kitty’s jacket goes unnoticed)

ANNOUNCER: After lightening their loads, the team silently sprints towards the summit. But then moments before reaching their destination, Clanci makes a shocking discovery. 

CLANCI: Oy, what is this?

Clanci confronts Kitty about her can of Pringles

CLANCI: Listen, hey, you know the rules! No snacking in front of the gorillas…(shaking head in disgust) Kitty, I had my doubts about you but I’m really starting to think that you don’t have the willpower and determination to execute this mission! 

A tussle ensues as Clanci tries to wrestle the can from Kitty

KITTY: Big boss, I got this. Give me another chance. We’re so close. I know I can make it. Don’t send me back now. You can’t do this to me.

CLANCI: If you want to hurt yourself, that’s fine. But you need to realize that you are not just putting your own life in danger… You are jeopardizing the lives of your teammates and my crew and that is completely unacceptable.

ANNOUNCER: After some further discussion, Clanci reluctantly agrees to let Kitty continue on. Clanci asks the park rangers to keep a close eye on Kitty in case any other incidents should arise.

ANNOUNCER: Then, the team enters the clearing…There, sunning themselves are the members of the Umubano group. There is a silverback male called Charles. He has many wives and a flock of children that are scattered around the field.

Gorilla relaxes after breakfast.

Much of the time is spent looking around, scratching armpits.

Tom takes a video of the gorilla family.

ANNOUNCER: After a few moments, the silverback rouses from his slumber and squints disapprovingly in Tom’s direction.

(Progressively more annoyed grunting noises)

CLANCI: Tom! Step out of the sunlight! The reflection off your head is agitating the male! 

My bad, sorry.

The silverback gets up and moves to a shadier spot.

There the scratching resumed…

ANNOUNCER: The trekkers look on in wonder as the gorillas gather as a family. There is the occasional rustle of leaves as more female gorillas emerge from the bushes to join the main group. Baby gorillas tumble along playfully after their mothers. Except for the buzzing flies and occasional breeze through the trees, the gorillas and the expedition members hold each other’s company in comfortable peaceful silence.

ANNOUNCER: Suddenly, a crunch shatters the air like a crack of thunder, sending a flock of birds into the sky. Everyone is shaken and all the gorillas raise their heads to find the source of the noise.

Kitty had managed to hide another can down her pant leg.

CLANCI: Kitty, NO! What’s you’re doing is extremely dangerous! You need to cease your snacking immediately!

“Whoopsie-doodles!”

The sound of Kitty’s snacking catches the attention of a baby gorilla.

He abandons the branch he was gnawing on and approaches Kitty.

As he gets closer, they lock eyes.

KITTY: I think that little guy just walked right up… and climbed into my heart.

(After some pause, the baby gorilla wanders back and returns to his mother. The team members try to get a hold of their emotions… But then suddenly, Clanci notices that the baby gorilla has a candy bracelet around his foot.)

CLANCI: Kitty! You’re unbelievable!

KITTY: What? I figured he would want something to remember me by.

ANNOUNCER: At the top of the mountain, time flies by in an instant. Jubilant team members pose for photos holding banners for their respective causes. They beam with smiles as wide as bananas.

TOM (breathlessly): The view from here is incredible. I’ve never witnessed anything like this before.

ANNOUNCER: While the team members celebrate, Clanci and the park rangers keep a close watch on time. In the final minute of the hour, the silverback majestically rises and lumbers off… Exit, stage right. One by one, baby gorillas climb onto their mothers’ back and follow the male into the bushes. Soon the clearing is empty as if a meeting had been adjourned or class had been dismissed.

We’re moving on, but leaving our hearts

TOM: This is such a magical experience, to be here and witness this first-hand. Not everyone gets to do this, it was truly humbling. I hope I can be an example to other hydrologists, to prove that they can get out there and do this kind thing.

CLANCI: What we need to remember today is that the park rangers are the real heroes. We are just visitors here, but they live on the mountain, protecting the gorillas with their lives. They’re built for this, they are a very special tribe of people. Good on them…

KITTY: Anyone up for dessert?

Indonesia’s flood warning to get a boost

Today there was an announcement about how Indonesia’s hydrologic monitoring system is going to get a major expansion.

Translated from Indonesian, “The flood early-warning system made ​​by Center for the Department of Public Works (PU) will soon be installed in 113 major rivers and dams in Indonesia.” …said Deputy Minister of Public Works, Hermanto Dardak, in London, Wednesday (2/5). Installation of early warning system equipment will be done nationally. A number of major rivers in Java would be a priority, such as Ciliwung, Citarum, Solo, and Cisadane. …“In addition to the early warning tools, we will also rehabilitate a number of streams to reduce the risk of flooding," he said. Head of Center for Public Works, Bambang Hargono, said the warning system was in development since 2006 and put into use last year.“

Last fall I went to Indonesia and wrote about meeting an observer involved with monitoring and flood early warning systems in Jakarta and have images of some of his equipment. All this was while we were trying to find the dirtiest spot on the dirtiest river in the world, and talk to some of the villagers that live along it. The most popular post on this blog is the one with photographs of the garbage. My main host during the visit was PUSAIR, the group that helped develop the flood early warning technology mentioned in the news release. Indonesia is also an adopter of Deltares’ FEWS (Flood Early Warning System), the same river forecasting software used by the US National Weather Service and the Australian Bureau of Meteorology. 

Thanks to Indonesian flood forecasting research scientist Segel Ginting for the link!

It never snows on a Sunday: Changes in the dates of winter snow surveys cause drifts in data

For 100 years now, snow surveyors have repeated a ritual of braving winter conditions to
measure high-elevation moisture in rugged terrain. But we don’t measure snow like they used to. For one, data collection agencies are less likely to go out in the snow on a weekend. There also has been a creep towards making snow surveys ahead of schedule; what used to be (and is still called) the “April 1st” survey is now taken closer to March 27th. '

In a newly published Climatic Change journal article, I analyzed the dates and day of the week of over 300,000 manual snowcourse measurements collected by the USDA’s Natural Resources Conservation Service. I found four previously undocumented factors that influence when people go and measure the snow. These subtle changes in human behavior have created biases in the datasets that are used for everything from water supply forecasting to studying climate change.

The inventor of snow surveys, James Church (upper right), using wooden snowshoes to get to a site. Bob Nault (center) measures snowpack in southern Utah in 2005. Nault and I drove hours to the site, then walked, but Utah usually makes extensive use of helicopters to collect the data. Almost all of James Church’s measurements were exactly on April 1st.
That’s not the case today.

Nault puts the sampler into the record-deep snow. When the tube comes out, it takes with it a core of the snow. Upper left is Garry Shaefer, recent head of the NRCS’s snow data collection program, with a sampler full of snow (photo courtesy of Phil Pasteris, former head of the forecasting program).

April 1st is like Groundhog Day for snowpack in the Western US. Roughly a thousand surveyors go to their respective stations every year to plunge metal tubes into the snow and draw out snow cores that are weighed for their water content. One group of surveyors arrives at a site with bare ground in April for the first time in 75 years and knows that the community must be warned of imminent drought. However, when the snow tube plunges to an unexpected depth, it could foreshadow bountiful crops or raging torrents.

Snow courses aren’t like climate stations where observers get up in the morning, make a cup of coffee, walk a few feet out their back door to measure rainfall and temperature and then go read the newspaper. Snow measurement sites are in some of the wildest and remotest places in the Western US including Alaska. Getting to them is a big endeavor so it’s typically only done once a month. These monthly reports are as anticipated, reported and scrutinized as the quarterly earnings announcements of businesses. 

To get the highest level of accuracy and consistency, all the data should be measured at the same date and time. However, it’s simply not practical to have everyone synchronize their watches and read their instruments exactly at the stroke of midnight on the first of the month. Most obviously, it’s dark at midnight and it is not safe to be wandering out in the snow. It’s cold, it’s easy to get lost, there are bears and there are avalanches. 

So instead of the “April 1st” reading, it’s more like the “sometime around April 1st” reading, depending on the person, the site and the situation (it can vary as much as 10 days early to 10 days late). Actually, what happens nowadays on April 1st is that the bulletins of the data are released to forecasters and the interested public, so the data has to be collected before that. If the data comes in late, it’s not included in the bulletins and gets labeled as missing, which is bad. People want timely products, so this has put pressure on the agencies to collect the data earlier and earlier. Before 1957, the data was collected on average one day before the first of the month. Now, it’s collected about two and a half days early.

Oregon snow surveyor Sheila Strachan measures the weight of the snow.

Another issue is weekends. If it was random, you would expect 2 out of 7 times the snowcourses would be measured on a weekend. But the earliness of the measurement depends on the day of the week of the first of the month.

Before about 1918, surveyors would faithfully measure snow exactly on the first of the month, regardless of what day of the week it was. From 1919 to 1957, the surveyors would tend not to measure on Sunday, but didn’t mind going out on a Saturday if the schedule demanded it. Nowadays, if the first of the month is anywhere close to the weekend, the surveys are typically taken on the Thursday before (not even Friday). Today’s surveyors are three times less likely to work on a weekend than their predecessors. Certain sites have gone decades never measuring on a weekend.

This reminded me of recent studies in the US and Australia showing how climate observers falsify recording zero without checking the gage if they think it didn’t rain. People often skip out of measuring on Sundays (reporting a zero), waiting until Monday to see what accumulated in the gage. People also like to record numbers divisible by 5 or 10, preferring to write down 0.45 inches even if the gage says 0.47.

Why does this matter? Imagine if you were taking an hour exam and you would get points taken off if you turned in your papers late. So instead you turn in your results about five minutes before the bell rings. The problem is that you’re losing those minutes that could be used to come up with better answers. It’s the same with snow data being collected on March 25th or 27th instead of April 1st.

Is this a big deal? A lot can happen in those final moments of the month, such as a big snowstorm. Last year the southern Utah site shown in the above pictures (Midway Valley) went from around normal to almost triple normal snow in the three days before Christmas. It is dangerous to be caught out during a major blizzard, so some surveyors might even check the weather forecasts and opt to get out and back before the snow falls. That’s contrary to the interests of those (like river forecasters) that would want that major event included.

Some years it doesn’t matter, it all just depends on the weather around the first of the month. When you average it over many stations and many years, collecting the data 3 days early means that February 1st measurements are roughly biased 5% of normal too low, and May 1st measurements are about 5% too high.

Read more on “Quantification of the influence of snow course measurement date on climatic trends” by Thomas Pagano in the journal Climatic Change.

Qanat Fever (Yazd, Iran)

Note: The International Center on Qanats and Historic Hydraulic Structures mentioned in the post below was funded by UNESCO (the United Nations Educational, Scientific and Cultural Organization). In October 2011, the US government cut off all funding for UNESCO (22% of the budget). This was because the agency voted to recognize Palestine at the same level as other member states. This triggered a 1990 law that caused the US to immediately stop payments to all UNESCO’s programs. UNESCO has a whole host of water-related programs from Tsunami early warning systems to famine relief. The agency also deals many fields of science from outer space to climate change. Even then, science is only one third of the name, education and culture being the other parts. Watch a very funny Daily Show segment about the issue here (including the second part).

At the very least, today you got a great Scrabble word: qanat (pronounced like “can not”). If you have a Q and no U, it’s one of only 33 possible words to play (qanats, plural, is also Scrabble legal). A qanat is a long horizontal tunnel driven into the side of a mountain. It gathers up the water that would be flowing underground and directs it towards faraway cities and farms. It’s like a well but horizontal, and there’s no pumping or energy required, the water just drains out on its own.

Cross section of a qanat. Water flows in from the left, drains out to the right.

Romans built their aqueducts around 2000 years ago to move water around; the Persians (Iranians) were doing much the same except the Persians were doing it underground and without slave labor. Some ancient Roman aqueducts are still being used and the same goes for qanats.

I saw my first qanat in Yazd, Iran while presenting at the First International Conference on Traditional Water Management in February. The purpose of the conference was to see if ancient cultures had any practices or solutions that would be relevant to modern water problems. I shared the Aboriginal Australian experience using material from Bradley Moggridge, CSIRO’s traditional water expert. The conference was sponsored by the UNESCO International Center on Qanats and Historic Hydraulic Structures (ICQHS) in Yazd.

With the UNESCO qanat center’s director A A Semsar Yazdi.

Strangely enough, I met a panel of qanat practitioners even before seeing a qanat in person. There was a panel discussion of them at the water management conference. They dig the tunnels and maintain them, and manage the water as it needs to be delivered to users.

I spent most of the session listening, while looking at the hands of one practitioner. His hands reminded me of those on ranchers I had known in Arizona; leathered and cracked, broad, pressed flat from punching cattle through the desert mountains. Hands like these only come from hard work outdoors. Me? I chew my nails because of nerves but that’s about it.

Qanat practitioners.

The practitioners described how some things had changed in the 2000 year history of qanats. Oil lamps have been replaced by electric lamps, now they use modern fiber ropes, use power tools, drive around in trucks, and so on. But the work still involved a lot of time with a pick axe moving dirt underground.

I don’t think I could have designed a more dangerous profession. These human moles wear white so they can be seen in the otherwise pitch-dark tunnels; their tunics double as burial shrouds in case they should be killed underground. Name another job where you would go to work in your funeral clothes.

Model of hand-powered crane (windlass) to bring water and dirt out of qanat tunnels. The person climbs on the rungs and it pulls the bucket up. 

From Francesca de Chatel’s book “Water Sheiks and Dam Builders”: Besides the danger of falling rocks and collapsing tunnels, they also risk drowning in sudden surging floodwaters [once the tunnels puncture the water table] and suffocating in the narrow spaces- no wonder that in Iran the qanat has been nicknamed “The murderer”.

The next day we went on a field trip to visit qanats out in the desert. As we drove the hour out of Yazd towards Meybod, the landscape got emptier and emptier. A couple hours in the other direction was the exact hottest place on earth (70 C/160 F surface temperature in the Lut Desert outside Kerman).

This is a fairly common scene outside Iran’s cities. Notice how the bushes are in rows, planted to control erosion and sandstorms 

When we arrived in the middle of nowhere (a phrase I’ll now use much more sparingly after seeing just how far you can get from everything in Iran), the only landscape feature was a series of perfectly aligned mini-volcanoes/oversized anthills. These were the ventilation shafts of a qanat below.  

A grate covers a qanat shaft. For human scale, there’s a person behind the second hill.

How qanat shafts look from the air.

These craters connect to a tunnel typically more than 20 meters (60 feet) down, and the deepest qanat goes down 275 meters (900 feet). Qanats are usually a couple miles long, with the longest reaching 70 kilometers (45 miles). As the qanat builders dug the underground tunnels, they had to be almost completely level, but drain slightly to push the water towards the outlet, much like modern sewer systems. Depending on the qanat, the tunnel level would slope down no more than the length of your forearm in the horizontal distance that you could cover in fifteen minutes of walking. Remember too that these were dug by hand tools centuries ago, lit by the flicker of an oil lamp.   

Entry to the Meybod mill.

In some places, however, a drop was intentionally added to the tunnel and the water was put to work. We visited the Meybod grain mill where 40 meters (120 feet) down, a qanat’s water would pour into a funnel and on to paddles to turn a millstone to grind grain. There was so much water going through this qanat that it could support two mills working fulltime. The tunnels were also useful when hiding from foreign invaders. For however many years these mills used to work, now they’re bone-dry because the water table has fallen due to unsustainable groundwater pumping. More details about Yazd’s water mills here.

As we were leaving the mill and driving back towards the city, we had qanat fever. Once you know what they look like, they seem everywhere. For example, what do you think those mounds are four pictures ago? We scanned the horizon for any visible lumps.

Is it? Could it be? Qanat!

For weeks, we had been spotting cones of debris alongside the road in Iran. I first saw these from an airplane, a field of symmetrical and evenly spaced piles, each about five feet tall and twice as wide. They were lined up like the studs on a bracelet or eggs in a carton. Someone explained that these were leftover construction material (bricks, dirt, wood, cement) that had been randomly (illegally?) dumped off by trucks. Those weren’t qanats.

Regular old roadside rubble.

Much like how it’s easy to confuse latrines for streamgages, every pile of rubble in the desert now looked like it was part of a qanat. And there’s lots of piles of rubble in Iran. But there’s also lots of qanats (by some estimates 50,000). Assembled end to end, Iran’s qanats would reach two-thirds of the way to the moon.

They’re not just in Iran… although invented and perfected by the ancient Persians, there’s qanats from Chile to China. At the traditional water management conference, the delegates from Algeria and Oman showed complex modern systems managed with GIS. They’re still very relevant because the technology is environmentally friendly and dirt cheap, on the order of tens of thousands of dollars.  

Back in the nearby town, we wandered through anonymous adobe-walled alleys until reaching a small locked wooden door with ancient metal fixtures.

Typical wooden door, with Valeriya Mladenova (a conference participant from Bulgaria).

Typical half-destroyed building in this region’s back streets.
Half not-destroyed if you consider yourself an optimist.

Beyond the locked wooden door was a passageway that led to a 40 foot deep pit, at the bottom of which was one of the qanat outlets. Such canals would run under houses and owners would draw out water as needed. The rest would go off to other uses, like bathing, farming and so on.

The qanat outlet is at the bottom of the stairs near the center of the photo. You would have to get on your hands and knees to crawl into it. Bring your oil lamp and hand shovel.

Humans at bottom for scale.

Again, qanat fever caused us to guess what other engineering marvels were tucked away behind the adobe walls of all the twisted back alleys? We tried to peek through the cracks of every locked wooden doorway but most were only abandoned homes. Later we visited a still-functioning qanat, having to ask four locals before finding it. It was just an unlabeled staircase down next to a traffic light, not too different from all the other unlabeled staircases next to traffic lights.

One thing about being a traveller is never being sure what you’re looking at, especially ancient structures. History is nearly always invisible unless there is someone there to tell the story. Now we were going to have to look at every tunnel, hole, pile, gate, ditch, field, wall, mound and doorway and wonder how many dozens of generations toiled anonymously to make these places thrive? Whose hands carved out each scoop of dirt to bloom otherwise sterile lands?

And where are those people now?

Small qanat still in use.