Well deepening

The well runs dry: what to do

Before deepening the well, find out why it runs dry. There are several reasons, and deepening helps with only some of them.

1. Measure the water column In the morning, before any water is used, measure with a cord and a weight how many metres of water there are in the well. Repeat in the evening and after heavy watering.
2. Watch the recovery If the water level recovers within a few hours after use, the well has inflow and only the reserve is too small. If the level has not recovered by the next morning, the inflow is weak.
3. Check the bottom A thick layer of silt and sand on the bottom blocks the inflow. In that case you first need well cleaning with a new bottom filter, and often that is enough.
4. Compare the consumption If the house has gained a dishwasher, a second bathroom, a pool or garden watering, the well may simply be too small for the new consumption.
5. Ask your neighbours If every well in the area runs dry, it is a seasonal drop in groundwater. If only yours does, the well's construction or depth is to blame.

Deepening is the right choice if the bottom is clean, the well runs dry every dry summer and there is an aquifer below it that can be reached. The building code provides for exactly this situation: if the well's yield is low, the well is deepened and extra volume is created to store water.

How a concrete ring well is deepened

1. Pumping out and cleaning We pump the well out and lift out the silt and the old bottom filter so we can see the edge of the bottom ring and the soil beneath it.
2. Digging under the rings We dig the soil under the bottom ring in stages from all sides so the rings settle evenly and do not tilt. A pump removes the inflowing water the whole time.
3. Stuck rings In old wells the rings are often stuck under the pressure of soil and frost and will not slide. Then we lower smaller-diameter rings into the well that go below the old ones, and we seal the gap between them.
4. A new ring on top Once the rings have settled, we add a new ring on top so the top of the well stays above the ground and surface water cannot run into the well.
5. Bottom, joints and disinfection We lay a new gravel and pebble filter, check and seal the joints, disinfect the well and let it fill up.

Deepening is best done at the end of summer or in autumn, when the groundwater level is at its lowest: then you can see how deep you need to go for the water to last through the next drought as well.

When deepening will not help

• There is a thick clay layer under the well: there is no water further down, and digging only increases the volume, not the inflow.
• The aquifer is thin and its full thickness is already in use.
• The rings are badly cracked or displaced: deepening can shift them even more. First you need well repair.
• The water consumption is higher than a concrete ring well can give: then a spike well (“spice” in Latvian) or a borehole is a better fit.

We tell you if deepening makes no sense and offer another solution. A new well in another spot is an option, but only if there is a better aquifer there: well digging.

Does deepening need documents

The Construction Law defines reconstruction as works that change the size of a structure, and renovation as replacing worn-out elements without changing the size. Deepening a well changes its depth, so it may be treated as reconstruction. For reconstruction of a first-group engineering structure, you submit an explanatory memorandum (paskaidrojuma raksts) to the municipal building authority (būvvalde). In practice municipalities assess this differently, so ask your building authority before the work.

How much does well deepening cost

Well deepening costs from €150. The final price depends on how deep we need to go and how many rings have to be added, and on the soil (sand, clay, stones, quicksand). It also depends on whether the rings slide or are stuck and need inner rings, and on how fast water flows in while we work. We agree on the ring material and delivery before the work. All prices: prices.