Pool construction in Algeria: Mediterranean climate, earthquakes and specifications

The average monthly high rises from 17.1 °C in January to 32.9 °C in August, and the average monthly low from 5.5 °C in January to 20.4 °C in August. The highest temperature ever measured is 48.7 °C, on 21 July 2023; the lowest is -3.3 °C. The annual rainfall of 685.2 mm falls on only 64.5 days; the wettest months are November (102.7 mm) and December (86.4 mm), and the driest is July (1.5 mm). Annual sunshine is 2,777.1 hours and average relative humidity is 67 percent; snow is very rare, and the last snowfall was in 2012.

From a pool engineering point of view, the two decisive rows in the table are November and August. In November, 102.7 mm of rain falling on only a few days means rainfall volume has to be added to the balance tank of an overflow pool and to the perimeter drainage. In August, an average high of 32.9 °C and strong sunshine push the water above 30 °C and burn off unstabilised chlorine; the hot wind from the Sahara (sirocco) carries dust and increases the load on the filter.

It killed 2,266 people, injured 10,261 and left around 200,000 homeless; more than 1,243 buildings were fully or partly destroyed and total damage reached 5 billion dollars. Around 400 deaths were recorded in the capital, Algiers, alone; the earthquake generated a 3 m tsunami that damaged boats in the Balearic Islands. Inadequate seismic engineering standards played a large part in the building collapses.

For the pool shell, this means the rules we apply in Turkey for Izmir and Istanbul also hold in Algeria: during an earthquake a water-filled shell sways under both its own mass and the load of the sloshing water, and if it is rigidly connected to a building, terrace or retaining wall, it cracks at the joint. A seismic joint with elastic filler and a waterstop is left between the shell and the structure; pipe penetrations are made with flexible sleeves and expansion joints; the balance tank sits on the same raft as the shell or is connected flexibly. Algeria's own seismic code (RPA) is the basis of the design, and the structural calculation is approved by a local engineer.

Pumps, filters, the heat pump, the dehumidification unit, the dosing system, stainless steel ladders and light fittings arrive by container from Turkey or Europe, and customs clearance and conformity certificates become part of the project schedule. The specification lists the brand, model, CE marking or equivalent certificate and spare parts list for every item; a part found missing on site means a delay measured in weeks. That is why the container list is derived from the commissioning list and a 10 percent spare parts allowance is added.

The second issue is labour. Structural works and finishes are carried out by Algerian crews, while pipework, the plant room and commissioning are done under the supervision of the Turkish technical team; the site languages are French and Arabic, and project notes are prepared in both. The third issue is operation: after handover the pool is run by local staff, so commissioning training is delivered together with a logbook in French, chemical storage rules and a weekly checklist. The common lesson from our exports to 14 countries is that a handover without training turns into a breakdown call within six months.

When the water exceeds 30 °C, the heater is switched off and the water is cooled by shading and night-time circulation; in hotel pools the reversible heat pump runs in cooling mode in summer. Chlorine is given in split doses through the day; the upper limit for cyanuric acid and the rate of partial water replacement are written into the specification. On sirocco days the surface cover is closed, filter pressure is checked daily and backwashing is done more often.

In this climate the plant room is a calculation of its own. In a city with a record high of 48.7 °C, the inside temperature of an enclosed plant room exceeds the limits for pump motors and electronic dosing equipment, so ventilation airflow, a shaded location and the motor temperature class go into the design. The chemical store sits in a cool, ventilated room separate from the pump room; because sodium hypochlorite breaks down quickly in the heat, only as much as will be used within the season is kept in stock.

The difference lies in the extremes and in logistics: the record high in Algiers is 2.6 °C above Antalya's, equipment is imported, and operation is handed over to local staff in French. Among the pool projects we have commissioned since 1993, Algeria is one of the markets closest to Turkey in climate and one of those that need the most planning in logistics.

The summary rule follows from this: pool construction in Algeria starts with a structural calculation to the local seismic code, the shell is separated from the building and the spa vessels by joints, the balance tank and drainage are sized for the November downpours, summer operation is set up with cooling and split dosing, the container list is derived from the commissioning sequence, and handover ends with operator training in French.