Urban Waterbuffer Valladolid

Short general project overview

In the last 20 years, Spain has lost 20% of its freshwater supply. Persistent periods of drought in Spain have increased the need to invest in water infrastructure. According to the latest data from the Spanish Ministry of Agriculture, Food and environment, water resources are at their lowest level since the 1990s (37% in November 2017) and in addition, many of the groundwater reservoirs are contaminated. In addition to increasingly prolonged periods of drought and water shortages, Spain is also increasingly suffering from heavy rainfall, leading to flooding and socio-economic damage. The overall balance between supply and demand suggests that there will be more water stress in Spain in the coming years – a serious problem that calls for an innovative and sustainable solution.
The Dutch start-up Field Factors wants to offer Spanish municipalities, water companies and large users of freshwater in urban areas a sustainable solution for fresh water supply, in such a way that it makes a positive contribution to the water balance. The Bluebloqs system is an innovative circular water management solution that is well suited to urban areas. By collecting, purifying, storing and reusing rainwater underground, a local Urban Water Buffer is created to ensure the availability of water in dry periods while preventing flooding by collecting rainwater This allows the buyer of water to ensure the continuity of its operations, which is reflected in a higher operating result and lower operating costs – at the same time, damage from heavy rainfall and flooding is prevented. The Bluebloqs system can be fitted into existing infrastructure, area development or restructuring assignments with a minimum above-ground space seizure. The combination of rainwater collection, purification, storage and reuse leads to a circular, sustainable solution for both water security and flooding.
The city of Valladolid, like the rest of Spain, is facing the effects of drought: low water levels and insufficient freshwater for irrigation of urban greenery and other urban functions. In addition, the city is severely affected by flooding and is experiencing more and more flooding due to peak rains. In extreme rainfall, the area around the Zorilla Football Stadium, where there is currently no rainwater drainage system, is flooded to handle the flow of approximately 15 hectares of paved surface. When it rains, the rainwater flows down the street towards the highway, causing a lot of nuisance. To solve these problems, the municipality wants to implement climate adaptation measures to collect as much rainwater locally as possible – an ambition of the municipality that fits perfectly with our solution. Hence the choice was made to do a first pilot in the city of Valladolid.

Initial activities and results of the project

The aim of this project is to implement and demonstrate the Bluebloqs technology in a pilot setup at the Zorrilla football stadium in Valladolid, thereby offering a concrete and cost-effective solution to the municipality of Valladolid, the water company Aquavall, the football club Real Valladolid, and other potential customers in Spain.

The specific goals are:

A. Realizing practical testing of The Bluebloqs technology in Spain related to purification, underground storage and recovery, and thereby accelerated local knowledge building so that potential customers can apply this water innovation.

• Creating trust: underground water storage, as we use it in the Netherlands, is not common in Spain. Especially when it comes to (microbial) water quality, licensees need to get acquainted with the technology;
• Optimization of retention and purification technology for potential pollutants in the local context in Spain;
• Test water quality over a longer period for safe reuse in a different climate.

B. Showcase the added value of the solution about the use of the subsoil for freshwater storage and the improvement of spatial quality.
The intended results of this pilot project are:

• The Dutch innovation Bluebloqs technology tested in the Spanish context;
• A final report with the conclusions and evaluation on the operation of The Bluebloqs technology in Valladolid;
• Applied a Dutch technology and brought it to the attention of potential customers and end users in Spain in order to realise market opportunities;
• Generating at least 2 new leads for scaling up Bluebloqs technology in Spain after the pilot. Within the pilot project, approximately 7 hectares of paved surface (stadium and parking lot) are disconnected to hold rainwater. The collected water is purified and infiltrated into the subsoil. The water is then reused to spray the sports fields.

The design of the pilot shall consist of the following components:

1. Reception system: draining water from the stadium is collected through an existing drain pit; in the parking lot, a drain in the upper catchment area and a low wall are placed at the lowest point.
2. Retention facility: a retention facility, dimensioned at an average shower of 12 mm, is created with an underground buffer (300 m3) and a rain garden (150 m3).
3. Biofilter: the collected water is then directed to a higher purification facility. This biofilter, dimensioned at 10 m3/h, consists of a sand filter as used at the Sparta stadium in Rotterdam (NL), but adapted to the water quality observed in Valladolid.
4. Infiltration wells: a crucial component is the infiltration and recovery of the water, which will be implemented in test cycles. First, the purification is carried out and evaluated. Then, small volumes of water are infiltrated by infiltration wells 25 meters deep, gradually increasing volumes and storage times.
5. Withdrawal wells: the water stored in longer cycles is recovered for irrigation by abstraction, approximately 17,000 m3 per year.