Alicante's Anti-Dana Safety Network

On 30th September 1997 the skies opened over Alicante. A 'cold drop' poured over the city all day. Up to 167 litres per square metre fell on the city, leaving basements and ground floors flooded, streets inundated, and vehicles and urban furniture floating, causing countless material damages and, tragically, four fatalities.

The water exceeded a metre and a half in some parts of the city, especially in streets near ravines like Juncaret, Bonhivern, or Orgegia, which regained their strength and flooded areas such as La Albufereta, Sangueta, or San Juan beach.

If in the previous floods in 1987 and 1982 the most affected area was the south of the city with San Gabriel as ground zero and an entire neighbourhood cut off, in 1997 the water moved north, just a few kilometres, turning the city's beach area into a quagmire.

When the waters receded, the feeling of abandonment gave way to a firm response. From there, Alicante implemented the first municipal anti-flood plan until 2005, a monumental work of over 40 kilometres of large channels, 18 of them beneath the city, which turned streets like the Rambla upside down. Beneath the capital's arteries lies a network parallel to its streets and avenues that allows water absorption in case of flooding.

However, it was not enough. Areas like San Juan beach continued to flood systematically, necessitating a second phase of infrastructure capable of collecting all the water, with the creation of the La Marjal floodable park, which celebrates its tenth anniversary in 2025.

The park is capable of retaining up to 45,000 cubic metres against high-intensity rain, and subsequently, diverting the rainwater flow to the drainage network or the treatment plant. It has never overflowed. The maximum accumulated was in 2019 when the pond collected 22,000 cubic metres, half its capacity. Another reference date was 13th March 2017 with 15,500 m³ of water. The park has stored a total of 58,350 cubic metres in this decade.

The success of this hydraulic system has led the Alicante City Council and the mixed company Aguas de Alicante to design new infrastructures forming an anti-dana safety network that protects the city during extreme weather episodes, to which we are increasingly exposed.

The so-called San Gabriel storm tank was built in 2011, occupying the underground of the 'Juan Antonio Samaranch' sports complex football field; 17 metres deep and with a capacity to retain 60,000 cubic metres of water that comes from rainwater collectors in case of torrential rains.

The tank is associated with a pumping station, which allows the water to be elevated to the Rincón de León treatment plant for treatment and reuse in street cleaning, park and garden irrigation, or agricultural land.

The installation was pioneering in Spain, and during the intense rain episodes that have hit Alicante in recent years, it has prevented the discharge into the Barranco de las Ovejas of large flows of dirty and contaminated waters, resulting from the storms.

But they are not enough. The City Council has planned new infrastructures to mitigate rain episodes and new tanks. Specifically, the construction of three new floodable parks and 12 anti-pollution and retention reservoirs is planned.

The new General Plan includes the construction of the Vía Parque-Teulada urban floodable park, currently in drafting. In addition to an urban park at the head of the San Blas ravine, in the vicinity of the Central Park, and a third urban floodable park on Elche Avenue, next to Casa Mediterráneo.

Regarding the reservoirs, there is a forecast of 12 new ones, which will have a total capacity of 150,000 cubic metres, distributed in sensitive points of the city, which will serve as containment and reduce the risks of pollution associated with occasional discharges on beaches, ravines, and coastal areas, highlighting those of Cocó, Palmeral, La Albufereta, Condomina, and the lower area of San Gabriel in the Paseo Joan Fuster environment.

Additionally, the City Council is developing various actions in the area of La Almadraba Beach, which, apart from renaturalising the area's environment, include various drainage elements and retention reservoirs, which mitigate the area's flood problems.

This sustainable drainage system in case of heavy rains will reduce the speed of runoff water, channelling its paths. For this, a 786 m³ cistern will be built with the function of retaining the rains and their subsequent discharge into the network, as well as an open channel to minimise drags to the beach and a filtering channel.