Challenge: Iain and Ellen to find water in one of the driest places on Earth. Kathy and Mike to purify the water; Jonathan to build a Mars Rover.
Owens Lake is one of hundreds of dry lakes, or playas, that the American West is home to. It is a legacy of a glacial past when enormous lakes, filled to brimming at the height of the last ice age, began to shrink as the climate sharply dried 10,000 years ago. More extreme drying over the last few thousand years continued the shrinkage, but the lake began to dry up in earnest in 1913 when local mountain streams and the Owens River that used to flow into it were siphoned off to water Los Angeles. This is where our search for water begins.
Surrounding our salt lake are stranded beaches, former lake shorelines that - like rings on a bathtub - are tell-tale geological evidence for the gradual disappearance of a large body of water. Our first stop of the day is at one of these high ‘fossil’ shorelines. Its well rounded beach pebbles showed clearly the signs of water action, as did the smoothed walls of a nearby outcrop of limestone. But the water was gone, and the ravines and gullies that had fed the lake were equally dry. Most of these dry stream channels were also carved out during the lake’s wetter glacial past, today carrying water only during the occasional rainstorms.
So instead our plan is to track up one of these dry stream beds to look for water higher up in the hills.
I can’t say that I’ve ever drunk my own urine before. I’ve not had the inclination or need. So it was probably a sign of the desperation that Ellen and I had got at the end of day 2 that drove me to sample my own bottled water.
Things had started well, with Ellen and I leading Kate to look for water up one of the main dry stream beds that winds up into the hills from the playa. Again there were signs of past flowing water in the smoothed rock surfaces, and as we press on Ellen spots the gradual vegetation changes that indicates the water table is getting closer to the surface. When it looks like it is a metre of so down, we can dig for it, and in the end the sign is pretty obvious – a small pocket of lush vegetation and trees growing in damp soil.
It looks as if the water is leaking up from a natural spring below, probably coming out at the contact between the sedimentary rocks (shales and sandstone) that we’ve been trekking through and the volcanic rocks (which appear to be dark basaltic lava) that start immediately upstream of the spring. The contact looks like a geological fault, a deep crack in the rocks that is a natural pathway for water. Still, we could have done with flowing or ponded water, but beggars can’t be choosers.
Kate, encouraged by our find, leaves us to dig. We film a spoof Iain-lets-Ellen-dig-the-holes sequence and then get on with really digging a few holes. Ellen actually does end up digging most of the holes, albeit under careful geological instruction, but they are dry.
The trouble is that we can’t dig exactly where the lushest vegetation is. An archaeological warden tells us that our spring ‘oasis’ could be the site where there might be native American or other historical cultural remains.
The historical cultural remains seem to be limited to a rusted iron pipe that once fed water to a mine close by, but our permits for filming are strict. We dig just down the slope, but there is no water.
Although we don’t hit water, the wet soil gives Ellen the idea to convert the holes to solar stills. This is where you stretch transparent polythene across a shallow hole and leave the sun to dry out the moist soil and organic matter – the evaporated moisture condenses on the underside of the plastic sheet, and trickles down into a collecting jar in the centre of the hole.
Although we do a few solar stills, we’re both not confident about the amount of water that we’ll get, so we come up with a couple of further ideas. Ellen goes off to ‘bag’ a tree (covering it in plastic sheeting so that moisture ‘exhaled’ by the leaves condenses) while I go off to pee in one of my holes.
Now it is rather unnerving being asked to urinate to order, and an even stranger sensation having a film crew record it for posterity. For me, it was a potential BAFTA-award-winning moment for cameraman Keith and sound recordist Rob, but for them, a clear low-point in otherwise esteemed professional careers.
The objective was to see if artificially adding ‘moisture’ to the soil in the hole might get that solar still to yield a greater amount of water. It is the same principle as before - the sun’s heat should evaporate off the water from those salts and chemicals that so spoil the taste of natural urine, leaving condensed moisture that is drinkable.
Drinkable, that is, only by the provider, because this process doesn’t filter out potential biological nasties. In the end, I don’t think Ellen minded missing out. Still, although a few hours of solar heating released only a trickle of ‘Scottish’ water, it wasn’t half bad.
(Producer's note: Sadly for Iain, his heroic sacrifice was sacrificed on the cutting room floor – there just wasn’t time to show it.)
Success at last! Although the solar stills had yielded only a few trickles of water each, the early morning trip up the valley with Kate revealed that overnight the bagged tree had given a good jar full. But it was becoming rather one-sided – Ellen’s botanical skills have produced a decent amount of reasonable water, whilst I have contributed a small sludge of chemical waste and a urine-infused dribble (which I drank).
Driving back past the Owens dry lake, I was anxious to redeem myself. It seemed to me that a line of vegetated mounds at the margin of the dried lake bed might be the trace of a springline, with the water seeping up from a subsurface fault below the lake. Dragging a bucket and spade, not to mention Ellen and a very sceptical Kate, across the hot salt-encrusted surface, we dug a few feet into the soft mud close to one of the mounds. Sure enough, water frothed into our hole.
Our director Alexis suggests that Kate should eat Humble pie by having to dig the main hole to get the water. So for the second day I get to relax while a girl does the work. One the one hand I feel that this is likely to get me slapped by irate females (including my wife, my mum etc) when the series airs, on the other hand it looks like pretty sweaty work in the midday sun!
Common sense prevails. Kate digs, we collect the water and, seriously behind schedule, we race off to get the water to Kathy and Mike.
Now this is when it gets strange. We get back to the shed to find that, alongside Kathy and Mike, putting the finishing touches to the water purification system is Lord Robert Winston. A fan of the show, he just happens to have ‘been passing’ after a conference in San Francisco (5 hours drive away!) and ‘popped in’.
(Actually he had arrived at our hotel the evening before, and he and a bunch of us then spent the night in a sleazy local bar playing pool into the early hours, with me partnering Robert to shouts of “I can’t lose. I’m playing with the Lord!’ Ah, simple things.) Anyway, he’s made an honorary rough scientist for the day (off camera) and is immediately put to work to help the water filtration. After all, as one of the leading fertility experts, he’s no stranger to tubes!
Meanwhile, the rest of us head off to test Jonathan’s mobile roving machine, Rover.
What a blast! The challenge is set up so the Rover is out of view over a small hill while Jonathan operates it via a home-rigged remote control system. (The man is a wizard.)
A monitor hooked up to a miniature camera on the rover allows us to guide it past a series of objects along a route laid out by the production team. Jonathan worries that the batteries may have been run down by earlier testing, but to the sound of his electronic commands, and our ecstatic screams, Rover jolts around encouragingly, hesitant at first but then ambles with increasing confidence. Against the odds and the heat, Rover was working! When it reached the finishing line and set off balloons, we just went mad with delight.
Still high from the Rover, it was back to the shed for the water testing. Waiting for us was a beaming Lord Winston with a selection of glasses of purified water. As the new kid on the RS team, it was perhaps no surprise that I had to blind-test our cheeky bouquets. There were four glasses of water: the solar still, the bagged tree, the lake-edge spring and a bottled water. Blindfolded, I had to choose the best tasting water, and in both takes picked out Ellen’s tree water – a clear success for Mike and Kathy’s purification system. And for me, the second-best water that I’d tasted in the last 48 hours!