Evaluating the Impact of Hotel Classification on Pool Water Consumption: A Case Study from Costa Brava (Spain)

Abstract

Swimming pools are key assets in the hotel industry. With climate change and water stress, more sustainable pools are needed in tourist areas. The study examines the relationship between hotel categories and the consumption of water in swimming pools in a Mediterranean coastal region facing water scarcity. The study focuses on the Costa Brava, with a focus on Lloret de Mar, a popular tourist destination. The research employs a combination of data analysis and the utilisation of evaporation models in order to estimate the consumption of water by swimming pools. The findings indicate that hotels in the higher categories, particularly those with three or four stars, contribute a notable proportion of the total water consumption due to their larger pool sizes and higher guest numbers. The study underscores the necessity for the implementation of sustainable water management strategies, particularly in the context of climate change. It recommends the utilisation of pool water-saving technologies as potential solutions. Furthermore, the paper highlights the broader environmental impact of tourism infrastructure on water resources and suggests policy measures to mitigate these effects. The research aligns with global sustainability goals such as the European Green Deal and the 2030 Agenda.

1. Introduction

Tourism is a driver of economic growth, but like any large-scale activity, it can have negative environmental impacts, particularly on water resources. The demand for water created by tourism poses a challenge to sustainability, especially when water is scarce, as is the case in the Costa Brava. Swimming pools are an important asset in the hotel industry and in the current context of climate change and water stress, the hotel sector must adopt more sustainable swimming pools that consume less water in coastal tourist areas under water stress, such as the Costa Brava.

The aim of this research is to evaluate the water consumption associated with swimming pools according to the category of establishments in this Mediterranean region, to achieve better water management in hotel pools. To this end, the study analyses different hotels in the Costa Brava, particularly the case of Lloret de Mar, and examines the impact of evaporation and water consumption according to hotel category, with the aim of proposing actions and strategies for the sustainable development of the sector and its swimming pools, in line with the 2030 Agenda and the European Green Deal.

The research methodology is grounded in an exploratory analysis primarily based on data sourced from the Spanish Land Registration Office’s website [1]. This involved downloading and analysing cadastral records of properties within Costa Brava municipalities, with a focus on identifying and examining swimming pools in hotel establishments. The study aimed to estimate the water consumption of hotel swimming pools in the Costa Brava and to assess the impact of the hotel’s star rating on this consumption, with a particular focus on the city of Lloret de Mar.

After the introduction, the literature review is presented, focusing on water consumption in hotels, with a particular emphasis on water consumption related to swimming pools in the hotel sector. The review distinguishes the water consumption due to evaporation according to the different categories of hotels and in relation to the tourist destination of Lloret de Mar on the Costa Brava, a municipality, which has the highest number of hotel swimming pools in this coastal area. The empirical part of the study is then presented, followed by the results, their discussion and the conclusions of the study.

2. Literature Review

In order to assess the impact of water consumption in swimming pools according to the classification of hotels in the Costa Brava, it is essential to consider the evaporation of water from hotel pools, the water consumption according to the star rating of the hotel, i.e., the hotel category and the specific case of Lloret de Mar, a municipality in the Costa Brava with more than 40,000 inhabitants, which has the largest number of hotel swimming pools in the Costa Brava.

The literature review is organised into three sections: evaporation, water consumption and hotel categories. Water consumption in the hotel sector is examined in the case of Lloret de Mar, which has the largest number of hotel swimming pools in the Costa Brava.

Evaporation is a major factor in the water consumption of hotel pools. It must be accurately calculated in order to highlight the resulting water loss. Therefore, appropriate formulas such as Penman’s should be used, with theoretical estimates of evaporation rates based on standard meteorological data [2,3,4]. These estimates should include various relevant parameters such as water temperature, air temperature, relative humidity and air speed, among others, to develop predictive models of water evaporation from pools with the aim of achieving more sustainable pools in the tourism sector [5].

An example of a more sustainable swimming pool that does not lose as much water to evaporation is a pool with covers [6]. On the other hand, the evaporation rates of pools under prevailing forced convection conditions improve the prediction models and allow the correction of excessive evaporation, according to the [7]. In the case of covered pools, in addition to the energy consumed to heat the pool water, evaporation of water from the pool surface increases humidity and affects evaporation rates, according to [8]. Therefore, the calculation of evaporation is essential for the prediction of pool water consumption [9]. It is noteworthy that the evaporation rate of the pool affects energy use and water consumption [10]. Furthermore, evaporation differs depending on the type of pool, i.e., indoor versus outdoor pools (both occupied and unoccupied), and evaporation should be calculated using appropriate formulas [11].

In the case of the Balearic Islands, which have a significant number of hotel pools compared to the rest of Europe and face a water scarcity problem, evaporation is a crucial factor. It is estimated using an empirical equation designed for open water surfaces, which combines standard meteorological data with a pool inventory to estimate water evaporation. The results show an increase in water consumption in Balearic swimming pools in 2015, especially in densely urbanised areas, due to the high evaporation rates of the constantly growing number of swimming pools in the Balearic Islands. This situation emphasises the need for responsible water management in these pools [12]. Our study follows this direction in the case of the Costa Brava.

Additionally, water consumption in pools, apart from evaporation, depends on the specific types of dwellings with pools. Specifically, water consumption in pools differs between detached houses with individual pools and community pools, which can be considered more socially equitable [13].

It is important to note that the Mediterranean region is one of the world’s leading tourist destinations and is affected by climate change and water demand. Furthermore, tourism consumes water, and as tourism grows, so does the demand for water. In particular, hotels consume a significant amount of water, especially in their swimming pools, with water consumption varying according to the different categories of hotels, which directly influence this water consumption [14]. Research on water resources in the hotel industry identifies key areas and academic research needs in this field to strengthen the sustainable development of the sector [15].

The water consumption of swimming pools varies according to the category of hotel. In the hotel sector, water consumption is essential for the sustainable development of the tourism industry. Good water management habits on the part of guests lead to greater water savings and more sustainable management of this resource [16]. Additionally, the length of stay of guests has a positive influence on water saving habits; particularly, longer stays contribute to improved water saving practices. Therefore, the hotel sector should promote extended periods of stay to improve water conservation [16].

Furthermore, according to the category of hotels (5, 4 and 3 stars) in the Canary Islands, 10% of hotels use water from desalination plants. This indicates that the energy and water consumption of hotels is sensitive and vulnerable due to their dependence on external energy and the significant need for water desalination, which poses a challenge to achieving more sustainable pools [17]. Moreover, some hotels have their own desalination plants and have progressively implemented water-saving measures in recent years, resulting in a significant reduction in water consumption and energy expenditure, with a positive impact on customer opinion and their pools [18].

The reality is that water consumption in hotels varies significantly from one to another, depending on factors such as hotel category, country, climate, size, facilities (spa, pools, gardens, kitchens, laundry, etc.), occupancy and more. In general, five-star hotels are responsible for a large part of the water consumption in the hotel sector, as reflected in the water demand of the Canary Islands [19,20]. In other areas, such as Benidorm, water consumption in tourist complexes decreases according to the size and category of the hotel. In particular, three-star hotels (common in Benidorm) show greater reductions in water consumption than four- and five-star hotels [21]. Furthermore, the star rating of a hotel influences its economic viability and the implementation of socially responsible practices, but not its environmental practices or the location of the hotel [22]. The star rating also influences the price of tourist accommodation, which is determined by private attributes (star rating, pool or sports facilities) and public attributes (natural environment, public safety or cultural heritage) [18].

Tourism is a key sector of the Spanish economy, as it is essential for the maintenance of the economic system. However, if environmental requirements are not considered, especially in terms of the sustainability of swimming pools, the country could face negative impacts on tourism, electricity and water consumption, depending on the star rating of the hotel [18]. It is also important to highlight that there is a relationship between the quality perceived by hotel customers and the economic performance of hotels; that is, the perception of higher quality by users is reflected in better financial performance, as in the case of Costa Brava [23,24].

On the other hand, hotels with the EU Eco-Management and Audit Scheme standard make efficient use of resources (including water consumption) and communicate key sustainability indicators to support sustainable tourism [25]. In the case of mass tourism, environmental stress in coastal regions has led to more efficient use of water resources, as seen in Lloret de Mar, a well-known mass tourism destination on the Costa Brava.

The expansion and contextualization of Lloret de Mar’s urban framework is important for understanding its development and water consumption patterns. Research shows that urban models significantly influence domestic water usage, with factors like demographic structure and socioeconomic variables playing important roles [26]. The proliferation of swimming pools in Mediterranean coastal areas, particularly in tourist-residential enclaves, has become a key feature of new urban landscapes, reflecting different urbanisation processes and wealth disparities [13]. Urban sprawl and socioeconomic polarisation have led to varying patterns of pool distribution in Southern European cities, challenging the notion of a homogeneous ‘Mediterranean city’ model [27]. Furthermore, construction booms, tourism-related immigration, land classification, and municipal surface area have been identified as influential factors in shaping urban dispersion ratios on the Spanish Mediterranean coast [28]. These findings highlight the complex interplay between urban development, socioeconomic factors, and water consumption in coastal areas like Lloret de Mar [29].

Lloret de Mar, with its large hotels that attract thousands of tourists per year, benefits from economies of scale in terms of water efficiency [30]. There are indicators to assess the efficiency of water consumption in hotels, such as the relative index, which compares current water consumption with an estimated minimum achievable value. Values greater than 1 reflect inefficiency in the consumption of water by the hotel [31]. With regard to hotel pools in Greece, it has been shown that water and financial resources are key to promoting the sector through ecomarketing, with water being a central feature [32]. Similarly, in Benidorm, a mass tourism destination, the water–energy nexus of pools has been highlighted, showing a strong correlation between water consumption and nonrenewable energy per night per guest in large hotels [33].

In the case of Lloret de Mar, a well-known tourist destination on the Costa Brava with a significant hotel industry, 175 swimming pools represent 46% of the total number of pools on the Costa Brava, making water consumption by type of hotel very important. In particular, spa guests can contribute to water savings during their stay due to their environmental awareness. For example, the Samba Hotel in Lloret de Mar conducted a cluster analysis that identified four types of guests with different levels of awareness and proactivity regarding water conservation. The study concluded that guests’ environmental awareness and engagement have a significant impact on water savings. Therefore, hotel operators should target these types of guests to save water according to the type of hotel, as is the case with a spa [34].

It is worth noting that tourists consume water to meet their basic needs and through leisure activities, such as relaxing in spas or swimming in pools [35]. In summer, water consumption peaks and water restrictions can affect the competitiveness of tourist destinations [36], as in Mallorca [37]. Therefore, the implementation of water conservation measures is essential in hotel management [38], although these measures are not without associated costs [39]. A study focusing on hotel managers in Lloret de Mar describes the implementation of water savings measures and explains the water efficiency initiatives adopted by hotels through a cluster analysis [34].

The results show that hotels with a large number of water-saving initiatives, which are highly proactive, tend to offer larger areas and belong to higher star categories, with hotel services such as pools, gardens or laundry, among others. In other words, services with high water requirements promote green practices that mitigate water consumption [34]. Furthermore, the year of building of a hotel does not reduce the degree of proactivity in water saving measures, although swimming pools should be made more sustainable.

The most proactive hotels are those that opened before the 1980s and have implemented processes to improve water use efficiency, often with environmental or quality certifications. On the other hand, small hotels, with fewer services and infrastructure requiring water, have a lower environmental impact and are less proactive [40]. Additionally, these hotels have fewer economic and technical resources for water conservation [39]. Furthermore, hotel chain affiliation does not seem to influence proactivity and environmental awareness.

Water savings are directly related to the reduction of economic costs, although some managers have the motivation to reduce their environmental impact through water savings in their facilities. It is observed that a high level of interest and environmental awareness is necessary to develop and implement water-saving measures in Lloret de Mar [34,41]. However, this is not enough, as other factors, such as having sufficient economic resources and/or technical knowledge, are important to reduce water consumption. A clear obstacle is the large economic investment required and the lack of knowledge in this area to save water. However, with the drought decree, progress is being made in this direction, with new water and tourism management, including swimming pools.

Our research focuses on Lloret de Mar, which receives significant tourist flows and where previous studies have identified five types of hotels with water-saving initiatives. These contribute to the promotion of awareness, proactivity and technological progress in the sector, with potential policies for aid, subsidies and tax reductions to save water [34,41].

The sector is currently experiencing economic growth but has significant environmental impacts. These are addressed by water reuse, which minimises water consumption but has an impact on carbon footprint, metal extraction and water footprint, as well as marine eutrophication, due to the treatment technologies used for potable water and greywater/wastewater treatment for reuse. The water footprint resulting from water reuse also highlights the widespread problems of water scarcity in Spain [42].

Tourism is a key driver of economic growth, but it has significant environmental impacts, particularly on water resources. The demand for water in tourism generates sustainability challenges, especially when water is scarce, as in the case of the Costa Brava.

Investigations of this particular aspect, focusing on Mallorca, conclude that the “all-inclusive” accommodation system can be detrimental and that water management systems in the sector need to be continuously improved [43]. Moreover, as a result of COVID-19, the impact on the tourism sector was significant and, in the case of Lloret de Mar, revealed a vulnerable production model when tourism is interrupted. Other indicators also show a complicated socioeconomic situation in Lloret de Mar, with lower income in the sector and reliance on public protection mechanisms [44]. Therefore, the business model needs to be reinvented, focusing on its key asset—swimming pools—and moving towards more sustainable pools that consume less water.

3. Materials and Methods

Hotel Classification and Its Impact on Pool Water Consumption

This study investigates the water consumption of hotel swimming pools in the Costa Brava region using exploratory analysis of data from the Spanish Land Registry (Catastro) [1]. It also examines how the star rating of hotels influences water consumption, with a particular focus on the city of Lloret de Mar. The study involved analysing the cadastral records of properties in the municipalities of the Costa Brava, focusing specifically on the presence and characteristics of swimming pools in hotel establishments.

According to the Statistical Institute of Catalonia (Indescat, Barcelona, Spain) [45] there are 397 hotels in the Costa Brava, representing 19.7% of all hotel establishments in Catalonia and 14.7% of the region’s accommodation in 2020. The distribution of hotels is concentrated, with six municipalities accounting for 65% of the total stock and Lloret de Mar alone containing 25% of the hotels.

Further analysis shows that 3- and 4-star hotels dominate the region, accounting for 65% of the total hotel offer in Catalonia and 75% in Lloret de Mar, as shown in Figure 1.

With the data of the Spanish Land Registry (Catastro) [1] the study identified 175 swimming pools within these hotel establishments, with Lloret de Mar having the highest concentration, accounting for 46.3% of the total number of pools. Figure 2 shows that 3- and 4-star hotels represent a greater number of pools, both for the total in Costa Brava, with 57%, and for Lloret de Mar, with 77%.

The data from the Spanish Land Registry include the surface area of the pool of each pool. Based on this information,

Table 1. Average surface area in m² of swimming pool by category of hotel and municipality (Source: Own elaboration based on data Spanish Land Registry (Catastro)).

Municipality	1 Star	2 Stars	3 Stars	4 Stars	5 Stars	Total
BEGUR	52.0		28.3	56.0	150.0	56.4
CADAQUÉS			111.5			111.5
CALONGE I SANT ANTONI	43.0			30.0		38.7
CASTELLÓ D’EMPURIES		67.3	172.0	32.5		94.4
CASTELL-PLATJA D’ARO	92.0	344.0		178.0	150.0	191
L’ESCALA		400.0				400
LLORET DE MAR	57.3	75.3	158.0	122.5	117.8	127.6
PALAFRUGELL	206.0		63.0	13.0		126.2
PALAMÓS	41.5	76.0	60.0		234.0	90.6
PALS	165.0			1060.0	62.5	234.3
ROSES		50.0	210.0			130
SANT FELIU DE GUIXOLS				53.3		53.33
SANT PERE PESCADOR	49.0	45.0	390.2			237.7
SANTA CRISTINA D’ARO			97.0			97
TORROELLA DE MONTGRÍ		97.9	70.0	50.0		89.1
TOSSA DE MAR		100.2	175.0	317.8		147.5
Total	86.3	102.8	161.3	145.2	115.1	130.7

provides a detailed breakdown of the average surface area (in square metres) for each hotel category and municipality on the Costa Brava. The average surface area of the entire inventory of swimming pools is calculated to be 130.7 m², with a total accumulated surface area of 22,879 m² for the 175 registered pools.

Evaporation in swimming pools is a critical factor affecting the water balance and its calculation depends on variables such as temperature, relative humidity, wind speed, solar radiation and pool surface area.

In the Costa Brava region, particularly in the municipality of Lloret de Mar, water evaporation is a significant problem, intensified by climate change [12].

This research aims to quantify water losses associated with hotel pools in the region, categorised by hotel classification and to analyse evaporation as the main source of water loss. In warm climates, such as the Mediterranean, evaporation can be a major contributor to pool water loss. Factors such as pool surface area, number of users, water and air temperature, relative humidity and water vapour pressure all modulate evaporation rates. Remarkable methods for calculating these rates include the ASHRAE formula and approaches developed in key works [3,4,9].

The average water surface area (m²) of the entire pool park is 130.7 m², similar to the 127.6 m² of Lloret de Mar. Additionally, the total water surface area in m² is 22,879 m² for all 175 pools installed in hotels on the Costa Brava, versus 10,339 m² in Lloret de Mar.

The average evaporation rates for the Mediterranean area, as found in the academic literature and industry data analysed, range from 5 to 8 l/m²/day throughout the year [12]. This calculation was made for the whole year, not just the summer season, as most pools remain full throughout the year during the low season and winter. This practice is recommended by the industry to save water and prevent problems with the pool structure.

As highlighted in the literature review, in the field of academic research on pool evaporation, several predictive models have been developed, [2,3,4,9]. These models, which are primarily based on experimental data, aim to estimate water evaporation from pools and other surface water bodies. In particular, many simulation models that predict the volume of water lost to evaporation are based on empirical approaches. These models typically evaluate evaporation as a function of various environmental parameters, highlighting the complex interplay between the environment and water evaporation rates.

Among these models, the Penman equation [2,3] stands out for its accuracy and consistency in predicting real-world evaporation data.

For the purposes of our calculations in this study, the Penman equation, presented in Equation (1), will serve as the basis for estimating the evaporation rates in our experimental setup. By using this historically significant and empirically validated equation, we aim to achieve reliable and accurate predictions of water loss due to evaporation in pools, thereby contributing valuable insights to ongoing research in this area.

$$E_0={\displaystyle \frac{\frac{700T_m}{100-A}+15(T-T_D)}{(80-T)}} ({\displaystyle \raisebox{1ex}{$\mathrm{m}\mathrm{m}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{d}\mathrm{a}\mathrm{y}$}\right.}).$$

(1)

where:

$$T_m=T+0.006 h,$$

(2)

$E_0$ is the evaporation value, in mm/day per unit area of the pool.

$T$ is the average temperature.

$A$ is the latitude, in the degree of the location.

$T_D$ is the temperature of Dew.

$h$ is the height above sea level of the location.

To perform the calculation, we also need the average meteorological data for the area. These data were obtained from the AEMET (State Meteorological Agency–Ministry for Ecological Transition and Demographic Challenge) website for Girona Airport, located in the town of Vilobí d’Onyar.

The data used for the calculation can be found in

Table 2. Monthly average atmospheric values of Girona Airport (Vilobí d’Onyar, Girona, Spain) (Source: AEMET).

TEMPERATURE	Average (°C)	January	February	March	April	May	June	July	August	September	October	November	December
	Max.	11.7	12.4	15.6	18.1	21.8	26.7	29	28.9	24.5	20.7	15.2	12.2
	Month average	6.4	7.2	10.2	13.1	16.8	21.5	23.9	23.7	19.8	16.1	10.5	7
	Min.	2.1	2.4	5	7.9	11.4	15.9	18.6	18.6	15.3	12	6.4	2.9
PRECIPITATION	Average (mm)	January	February	March	April	May	June	July	August	September	October	November	December
	Month average	43.5	42.8	42.3	49.5	47.4	29.7	19.7	23.6	43.9	69.1	63.4	41.8
WIND SPEED	Average (kph)	January	February	March	April	May	June	July	August	September	October	November	December
	Month average	20.2	20.5	19.8	18.6	16.2	14.8	15	14.7	15.7	17.4	20	20.6
	Wind speed (m/s)	5.6	5.7	5.5	5.2	4.5	4.1	4.2	4.1	4.4	4.8	5.6	5.7
WATER TEMPERATURE	Average (°C)	January	February	March	April	May	June	July	August	September	October	November	December
	Month average	13	13	13	14	16	19	21	22	21	18	16	14
RELATIVE HUMIDITY	Average (%)	January	February	March	April	May	June	July	August	September	October	November	December
	Month average	0.79	0.74	0.72	0.71	0.7	0.64	0.62	0.64	0.71	0.76	0.77	0.78
DEW POINT TEMPERATURE	Average (°C)	January	February	March	April	May	June	July	August	September	October	November	December
	Month average	3	2.9	5.4	8	11.3	14.4	16.2	16.5	14.4	11.9	6.6	3.4

.

To calculate the evaporation rate, we also consider the latitude in degrees of Girona Airport (Vilobí d’Onyar) as a middle point in the Costa Brava, which is located at:

• Latitude: 41°54′42″ N (41.91166667°)
• Longitude: 2°45′48″ E

Using this data, we obtain

Table 3. Calculation of the average monthly evaporation index according to the Simplified Penman formula [4] (Source: Own elaboration).

Penman	January	February	March	April	May	June	July	August	September	October	November	December
Tm	6.43	7.23	10.23	13.13	16.83	21.53	23.93	23.73	19.83	16.13	10.53	7.03
(T-Td)	3.40	4.30	4.80	5.10	5.50	7.10	7.70	7.20	5.40	4.20	3.90	3.60
Evaporation (E0) mm/day/m2	1.75	2.08	2.80	3.51	4.51	6.26	7.20	7.00	5.32	4.03	2.67	1.90

, which presents the average evaporation index per unit of surface area:

To incorporate the variable of pool occupancy, the formula developed by M. Mohammed Shah in the latest revision of his study Improved Model for Calculation of Evaporation from Water Pools (Shah, 2018) [9] has been used. This calculation is introduced into the following Formula (3):

$${E_{occ}/E}_0=1.3U+1.2.$$

(3)

On:

$$U={\displaystyle \frac{4.5N}{A}},$$

$E_{occ}$ is the evaporation index for the occupied pool (mm/day/m²)

$E_0$ is the evaporation index for the unoccupied pool (mm/day/m²)

$U$ is the pool utilisation factor

$N$ is the number of pool occupants

$A$ is the surface area of the pool in m².

In order to calculate pool occupancy, we refer to the design regulations for public pools, a category that includes hotel pools. These design regulations vary depending on the country and the Autonomous Community. In Catalonia, the applicable sanitary regulations for public pools are outlined in Decree 95/2000, dated 22 February, published in the Official Gazette of the Government of Catalonia, No. 3092, on 6 March 2000 [46], which establishes the sanitary standards applicable to public pools. The decree states that the maximum occupancy limit should be one person per 2.5 m² of water surface.

Taking this limitation into account and considering that calculations are made for the average pool occupancy, recognising that pools are not always at full capacity throughout the day, the following relationship between the evaporation index for an occupied pool (E_occ) and the evaporation index for an unoccupied pool (E₀) is calculated:

$$U=4.5\ast {\displaystyle \frac{1}{2.5\ast 4}}=0.45.$$

(4)

Subsequently:

$${E_{occ}/E}_0=1.3\ast 0.45+1.2=1.785.$$

(5)

$$E_{occ}=1.785\ast E_0$$

(6)

This means that the evaporation of water is almost 1.8 times higher when the pool is occupied than when the pool is unoccupied and the water is calm. This parameter was used only during the high season, from May to September, the rest of the months being considered unoccupied.

Finally, Formula (6) is applied in order to calculate the total evaporation for occupied pools (See

Table 4. Calculation of the average monthly evaporation index according to occupied pools [9] (Source: Own elaboration).

Occupied Pool Evaporation	January	February	March	April	May	June	July	August	September	October	November	December
Evaporation (E0) mm/day/m2	1.75	2.08	2.80	3.51	4.51	6.26	7.20	7.00	5.32	4.03	2.67	1.90
Eocc/E0	1.00	1.00	1.00	1.00	1.79	1.79	1.79	1.79	1.79	1.00	1.00	1.00
Evaporation (Eocc) mm/day/m2	1.75	2.08	2.80	3.51	8.07	11.21	12.89	12.53	9.52	4.03	2.67	1.90

):

If the average evaporation index is recalculated considering the pool occupancy, we find that it would be 6.1 l/day/m², which is entirely consistent with the research based on the more empirical methods mentioned earlier [12].

With the comprehensive data that have been collected and analysed, we now proceed to an in-depth analysis and calculation of the evaporation rates of the water in the swimming pools of the Costa Brava.

This analysis will first categorise the evaporation totals based on hotel classifications, providing an overview of the region. This will be followed by a more detailed calculation specific to the municipality of Lloret de Mar.

4. Results

The research analyses the water consumption and evaporation rates of hotel swimming pools in the Costa Brava, with a focus on Lloret de Mar. The main results show significant differences in water evaporation between the Costa Brava as a whole and Lloret de Mar, as well as between different hotel categories, as shown in the data on evaporation by hotel category in

Table 5. Evaporation rate of the swimming pools of the hotels on the Costa Brava and Lloret de Mar by hotel category (Source: Own elaboration).

Hotel Category	Costa Brava		Lloret de Mar
	Pools Surface (m2)	Evaporation (m3)	Pools Surface (m2)	Evaporation (m3)
1 star	1812	4034	401	893
2 stars	4110	9151	301	670
3 stars	8551	19,039	4898	10,905
4 stars	6680	14,873	3797	8454
5 stars	1726	3843	942	2097
Total	22,879	50,940	10,339	23,020

:

These results aim to provide a clearer understanding of the impact of pool water evaporation both in the wider Costa Brava area and in the localised context of Lloret de Mar. This approach will help to identify patterns and variations in evaporation rates that may be influenced by factors such as hotel size, location and climatic conditions. See Figure 3.

Lloret de Mar has a high concentration of pools in 3- and 4-star hotels, representing 84.1% of the total pool surface area and a similar proportion of the total evaporation. This contrasts with the Costa Brava as a whole, where 3- and 4-star hotels account for 66.6% of the total pool surface area and evaporation.

Lower category 1- and 2-star hotels represent a significantly smaller percentage of the total pool surface area and evaporation in both Lloret de Mar and the Costa Brava, with Lloret de Mar having a smaller proportion of these hotel categories compared to the overall region.

These percentages underscore how hotel category impacts both the distribution of pool surfaces and the corresponding water evaporation. This is particularly notable in Lloret de Mar, where most water evaporation is attributed to higher-category hotels. This suggests that mid- to high-end hotels have a larger environmental footprint in terms of water usage, a factor that should be considered in regional water management and conservation strategies.

The study of the water consumption and evaporation rates of hotel swimming pools on the Costa Brava, and specifically in Lloret de Mar, provides some key insights into the environmental impact of the tourism industry, particularly in relation to hotel categories. The results highlight the importance of understanding the differential relationships between hotel classification, water consumption and environmental sustainability.

4.1. Concentration of Resources in Areas of High Tourist Density

Lloret de Mar, as a major tourist destination within the Costa Brava, shows a higher concentration of swimming pools in 3- and 4-star hotels. This concentration is significant not only because these hotel categories represent most accommodation options, but also because they are associated with larger pool areas and consequently higher evaporation rates.

The fact that Lloret de Mar accounts for almost half of the total pool area and water evaporation in the Costa Brava, despite its smaller geographical and infrastructural footprint, highlights the disproportionate demand for resources placed on this municipality. This demand is likely to be intensified during peak tourist seasons, contributing to local water scarcity problems and increased pressure on municipal water resources.

4.2. Impact of Hotel Category on Water Use

The data clearly show that higher category hotels, particularly those in the 3- and 4-star range, are the main contributors to water evaporation in both the Costa Brava and Lloret de Mar. These hotels not only have larger swimming pools, but also provide for a higher number of guests, resulting in increased water consumption for both recreational and maintenance purposes.

4.3. Environmental and Policy Implications

The results of this study raise important questions regarding the sustainability of current tourism practices in the Costa Brava, particularly in water-stressed areas such as Lloret de Mar. The high evaporation rates associated with hotel pools, especially in the context of climate change, necessitate the development of targeted water conservation strategies.

Local and regional governments, in collaboration with the hotel and pool industry, should consider implementing measures such as the use of pool covers, optimised water circulation systems and stricter regulations on pool size in relation to hotel capacity.

From a policy perspective, there is a need for stricter regulations that take into account the cumulative impact of tourism infrastructure on water resources. This is particularly important in Mediterranean regions where water scarcity is a constant concern. Policies could include incentives for hotels that adopt water-saving technologies and penalties for those that exceed certain water use thresholds.

4.4. Wider Implications for Sustainable Tourism

The case of Lloret de Mar serves as a microcosm for examining the broader challenges of sustainable tourism in coastal regions.

To address these challenges, there is a growing need for the tourism industry to adopt more sustainable practices. This could include rethinking the design and operation of tourism facilities to reduce their environmental footprint, including the promotion of ecofriendly tourism models that emphasise resource conservation.

Additionally, the results of this study could inform the development of educational campaigns aimed at tourists to encourage them to be more mindful of their water use during their stay. By promoting a culture of sustainability among both tourists and hoteliers, it may be possible to balance economic interests with the need to conserve natural resources.

The findings of this study not only underscore the environmental challenges associated with hotel swimming pools in high-tourist-density locations such as Lloret de Mar but also establish a foundation for future research and policy development aimed at promoting sustainable water management in the hospitality industry.

5. Discussion

The study offers valuable insights into the relationship between hotel classification and water consumption, with a particular focus on swimming pools in the Costa Brava region. The analysis revealed significant differences in water consumption and evaporation rates between different hotel categories, with the highest water use observed in hotels with three or four stars. These findings are consistent with the existing literature, which emphasises the substantial influence of hotel category on water use [14,21].

Furthermore, the urban context of Lloret de Mar is a significant determinant of the municipality’s water consumption patterns. The expansion and urban development of the town have been identified as significant influences on domestic and tourism-related water usage. As research indicates, urban models, demographic structures, and socioeconomic variables are significant factors in determining water demand [26]. The proliferation of swimming pools in tourist–residential areas, such as Lloret de Mar, reflects broader trends in Mediterranean urbanisation, which often result in increased water demand in wealthier and more sprawling urban enclaves [13]. This urban expansion and associated socioeconomic polarisation have shaped the distribution of swimming pools, challenging traditional models of a homogeneous ‘Mediterranean city’ [27]. The urban development of Lloret de Mar, shaped by construction booms and tourism-related immigration, has resulted in varying patterns of water use, thereby further contributing to the complexity of water management in the region [28]. The expansion of the town’s infrastructure and the increasing number of tourist accommodations have led to an intensification of water consumption, particularly during the summer months when the population swells due to the influx of tourists. This emphasises the necessity for targeted water conservation measures that consider both hotel operations and broader urban planning strategies.

The high concentration of three- and four-star hotels in Lloret de Mar, which account for 84.1% of the total pool surface area and water evaporation, serves to further emphasise the disproportionate environmental impact of mid-range hotels. This trend is consistent with findings in other tourist-heavy regions, such as the Canary Islands and Benidorm, where higher-star hotels have been shown to significantly contribute to water consumption, particularly due to the larger size of pools and associated guest usage [17].

Evaporation represents a significant factor contributing to water loss in hotel swimming pools. This observation lends support to the findings of Asdrubali (2009) [5], who emphasised the importance of accurate evaporation calculations in the management of pool water loss. Furthermore, the existing literature indicates that hotel guest behaviour can also exert an influence on water consumption. For example, longer guest stays have been linked to more sustainable water usage habits [16]. This finding indicates that hotels may be able to reduce water consumption by promoting longer stays and educating guests about water-saving practices. The study’s findings, which indicate a higher prevalence of pools in hotels with larger facilities, also underscore the necessity for enhanced water management practices in higher-category hotels, particularly during peak tourist seasons when demand for water resources is at its highest.

In terms of policy implications, the study reinforces the necessity for more stringent regulations regarding water usage in the tourism sector, particularly in regions experiencing water scarcity, such as the Mediterranean. In light of the anticipated exacerbation of water scarcity as a consequence of climate change, local authorities would be well advised to consider the implementation of water-saving technologies, such as improved circulation systems and pool covers, in addition to the promotion of ecofriendly certifications such as the EU Eco-Management and Audit Scheme, which have been linked to more efficient resource use in the hotel industry [25]. Moreover, policies that encourage hotels to adopt sustainable practices, particularly in relation to water conservation, could play a pivotal role in reducing the environmental impact of tourism in coastal regions.

In conclusion, the rapid urban expansion of Lloret de Mar and the concentration of tourism-related facilities present considerable challenges to the implementation of sustainable water management strategies. The relationship between urban development and water consumption is intricate and necessitates integrated strategies that encompass both urban planning and hotel operations [29].

6. Conclusions

The conclusions of this research highlight the crucial need for the hotel industry, particularly in water-stressed regions such as the Costa Brava, to adopt more sustainable practices in the management of swimming pools. As a key asset in the hotel sector, swimming pools contribute increase sales of the sector and at the same time add water consumption and their impact is magnified in areas experiencing high tourist volumes and water scarcity due to climate change. The current state of hotel pools, many of which are ageing with an average age of 34 years [47], presents numerous opportunities for improvement through the adoption of modern technologies that can drastically reduce water loss, such as pool covers and rainwater harvesting systems.

Additionally, the investigation points to the growing importance of environmental sustainability within the hotel industry, driven by increasing stakeholder awareness. This shift makes the goal of reducing the water footprint of swimming pools more achievable. However, the study recognises the highly seasonal nature of tourism in coastal areas, which increases environmental stress during peak seasons. Therefore, the implementation of technologies that improve water efficiency is vital to mitigate these impacts.

The limitations of the study include the indirect nature of the data collected, specifically the estimation of water consumption based on evapotranspiration. To improve accuracy, future research should employ more direct data collection methods, enabling the acquisition of precise information from the hotels themselves. Such methods would not only enhance the reliability of the findings but also allow for the validation and refinement of the current methodology.

The findings underscore that the future of the tourism industry depends on improved sustainability across social, economic and environmental dimensions and that targeted research and policy initiatives are needed to reduce the sector’s impact and ensure long-term benefits for all stakeholders.