This year the drought was especially bad. By early march a 7-meter-deep well we dug twelve years ago was almost dry. It was at least another month and a half or more until the rains would come. This well is mainly used in irrigation plants. The ornamental and edible plants were suffering. Covid 19 had arrived and the business was paralyzed, so a pending project was started, which was a second well.
How to select a site?
Obviously if there is a wet area on your property then explore that first. Some say look where the plants are greenest most of the year. Although this might be a good place to drill a well, it is not always an indication of what is under the ground. Shade makes the soil more humid, for example, so that one can get a false idea of what is below the surface. We live in a high valley that I think was once a lake covered by a Plinian volcanic eruption. The soil is deep, up to 300 meters in places without hitting bedrock. The upper layers of the soil are clayish and hard during the dry season, at least up to 15 meters deep. It is reasonably safe to dig a well here without a caisson for protection. There are parts of the valley where you can hit the water at 2 or 3 meters or others where the water is more elusive. For us it was a toss up. We just chose a convenient place behind the house.
To Begin:
We decided to make a well that, when lined, would be 1 meter in diameter. First we drew a circle on the ground 1.80 meters in diameter with lime. We dug down approximately 60 centimeters respecting our perimeter of 1.80. Here we costructed a base to hold the well ring made of stone and to support two columns. The columns would support a cement beam into which was imbedded a steel ring used to raise the rubble. (See the images below). We began with pick and shovel and gusto confident that we would find water. I think men just love holes and dirt. In the last lines of Death of a Salesman it states: "He was a happy man with a batch of cement"
Base of block, cement, and supports for the columns
Hard balls of earth
Excavation resumed. We filled buckets with soil and brought them to the surface as we edged slowly downwards. The usual stupid coversations about hitting buried treasure or oil emerged. How to divide the profits wasdiscussed. I am the owner of the property but I told my two helpers that I would not forget them if we struck dubloons or an oil seep. Then I told them of the story of Bluebeard The Pirate and how he preferred deserted islands to interr his loot, and how he would bring two of his thugs ashore with him to help with the excavation,,, then when the work was done he would finish them both off with his pistol and roll them into the hole with the treasure their spirits guarding it until Bluebeard returned. And of course dead men tell no tales.
Columns, beam, and stone ring
The air was warm and the work difficult, but there was time to talk. Like Sisyphus who had time on his hands to think when he went downhill to retrieve his rock we made idle conversation and even bets when we would reach water. I bet three meters, Aurelio 4.5 and Hugo the pessimist of the group,5 meters. At about 2.3 meters we find some pieces of wood, probably from the last volcanic eruption and floodingof the area with a massive lahar. Amidst the wood and in a line downwards there were soft rocks. In this soil there is very little rock, almost none. You would die of hunger looking for one to break a bakery window. Finding stones for me was a good sign. The water under this compact soil, I thought, would probably benefit from following some rocks to find their way out. At 2.4 meters, the earth was becoming saturated with moisture. At almost exactly 3 meters from the surface, Hugo, the pessimist, jammed his shovel into the ground and when he turned it over there was a puddle that seemed blue to us on the surface,,,a reflection of the sky.
Very nice moment. Water! Excavation continued with increased vigor yet increasing difficulty. The earth became more and more saturated and the journey to the surface longer. When the excavation stopped, we could see small veins of water bubbling up from below or coming out of the walls of the well. The next morning we woke up to 1.20 meters of water in the hole. I calculated about 1200 liters. It was a godsend because the plants were in desperate need of a good soaking.
We decided to stop 6 meters deep to have a good reserve. If we had struck water at three meters in the driest days of the year and the well produced 1200 liters of water at night, that meant that there would always be water available. Doesn't take a genius to come up with that last sentence
As we descended towards our goal, it seemed that the water veins originated at about 5.5 meters, mainly from the walls of the well. When we reached 6.25 meters we stopped digging. and we put a 15 centimeter bed of gravel at the bottom of the well. I decided that it would be better to line the well from the bottom with 1.20 meters of brick, leaving spaces between the bricks for the water to enter. Brick is porous and any other water emmanating from the walls would eventually saturate the brick and enter the well space. From 1.20 meters to ground level, we wanted to line the well with cement. This would limit surface contamination during the rainy season here, when you can dig a hole and find water within 12 inches of the surface.
Laying brick from the bottom of the well up to 1.20 meters. Note the plumb bob at the right in the foto
The next stage took some time. I made a 1 meter diameter drum with two circles of plywood, some thin boards and 60 cm of polycarbonate sheet. A 1/2 inch metal rod was inserted into the center of the drum and a star pattern of rebar was welded at right angles to the metal rod where it exited the bottom of the drum. When the metal bar came out of the plywood top piece, I welded three nuts together on top of the 1/2" metal rod to make a sleeve. Then I welded a ring made from three turns of what we call alambron here to the bolt and screwed the bolt into the metal bar home made sleeve. See the second foto below. The idea was to insert the drum form into the hole, center it, and pour cement between it and the earthen walls of the well. When the cement was slightly cured (after an hour or less, depending on conditions), we could carefully pull out the drum form attached to a come-a-long.
Tambor. Puedes ver la varilla de metal con anillo. El tambor medi 1 metro diametro y 60 cm altura.
The ring welded bolt screwed into its sleeve of nuts
We found that a slightly sand-heavy, cement laden mix was better. We used long bamboo poles to compact the cement. It was determined that we needed to make 9 pours of 50 cm each to reach the surface. We already had 1.20 meters of brick at the bottom and the well was 6.25 meters deep. Sounded great but I was nervous. To test the device we poured only 40 cm the first time, not the full 60 centimeters of the drum. We compacted he cement around the form with the bamboo poles.
You can see the bamboo poles that we used to compact the cement and also see the drum at the bottom of the well. The cement was poured between the drum and the earth walls of the well.
We used a 6" PVC pipe to direct the cement. In the foto you can see Aurelio holding the 6" pipe and Hugo, the pessimist, with his baby shovel. The come-a-long is visible in the center of the foto.
Persuading the drum by pulling with a lasso at right angles to the lasso attached to the drum. This action loosened the drum a little from the cement.
We discovered that the cement pressed tightly against the drum. I cannot stress enough getting the right mix, not too wet or too gravely. The first pour put a lot of pressure on the lifting device (come-a-long) and the structure of the drum. I was afraid that we would lose everything down the hole. In fact the first time we tried to pull up on the drum it seemed completely stuck in the hole. Oh shit I thought we better find some dynamite but then again I panic easily. It was discovered we needed to persuade the drum by pulling its lasso with another rope at a perpendicular angle (pictured above). When the mix was still flexible (30-60 minutes), this method worked very well. Pull at a perpendicular angle from various positions and then lift a little with the come-a-long. Pull and lift. When the drum was freed we pulled it upwards but without completely exiting the pour. We always left about 10 cm of the drum inserted in the previous cast. The next day we would remove the drum, clean it and reinsert it into the casting from the day before..
The well with alittle water. You can see the brick lining below and the cement lining above it and finally some levels of brick.
Finishing the above ground ring and forming a rounded edge by hand.
The top in two pieces poured in place. We used a sheet of plywood for a base and polycarbonate for the circular form. Blocks of 2x4 held the poly in place.We buried rings in the cement in order to lift the two halves when cured. .
Top complete and in place
The completed well with an access door made from stainless steel.
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