Determinants of Water Consumption in Hotels: New Insights Obtained through a Case Study

Abstract

The literature on water use in hotels has identified numerous determinants of water consumption, but a consensus has yet to be reached on the influence of some of these factors. This article aims to enhance the current research framework on water use in the hotel sector by presenting a case study of one hotel in Tenerife, Canary Islands. The conceptual framework of water consumption in hotels is presented based on the previous literature. Starting from that, basic statistical analysis and bivariate correlations were performed on water consumption data from 2007 to 2019 to determine the significant factors affecting both total water consumption and consumption per guest night. Special attention was paid to water usage in gardens and the impact of weather conditions, as there is a lack of research focused on them. Additionally, the water management actions of the hotel were classified according to the business’ themes proposed for the Sustainable Development Goals, using an internationally recognized guide, thus addressing one of the gaps identified in the literature. The results generally support previous research findings, but some discrepancies were noted regarding the number of guest nights and the effectiveness of implementing water-saving measures. This raises new questions about the characteristics of various water-saving measures, such as room renovation, and their influence on customer behavior, which may alter the intended impact on water consumption. Therefore, the findings of this study can provide an insight into unclear aspects in this area. They could also benefit hotels in terms of sustainability communication by allowing them to position their actions with an internationally recognized framework.

1. Introduction

Water is a crucial topic on the sustainability agenda, with access to safe drinking water and sanitation recognized as human rights by the United Nations [1]. The accurate measurement of water use and availability has been an important aspect related to the Sustainable Development Goals (SDGs). The contribution of the private sector, including the tourism industry, to improve water management, seems to be more related to “aspects of strategic execution” [2] (p. 1), meaning that the ethic and/or social component is still missing in most of the cases. Nevertheless, implementing correct water management, with special focus on measurement, is not only a moral or legal obligation for businesses but it can result into added value for private organizations, as noted by [3].

In the tourism industry, water is one of the most strategic natural resources, and, within it, hotels are considered one of the main consumers of water [4,5,6,7]. However, the inefficient management of this resource can cause serious environmental problems, particularly in areas where water scarcity coexists with high demand [8,9,10]. Seeking ways to save water is essential, especially in geographical areas where water availability is limited, and tourism activities put pressure on water resources [11]. Therefore, a better knowledge on the factors that determine water consumption could translate into both benefits for the hotels and for the destination.

The importance of understanding the variables of water consumption in hotels is reflected in the study of [12] who structure research on water resources in the hotel sector into four groups: water consumption, water management, impacts of water use, and good practices. Among these groups, a great part of the article was focused on identifying significant variables affecting water consumption and its measurement. Factors of different nature have been defined to influence water consumption in hotels. Some of the articles highlight hotels’ physical characteristics as being determinant in their water consumption [13,14]. Others point out the importance of water-saving measures such as environmental certification, implementation of water-saving devices, etc. [8,9]. Several studies focus on the role and structure of water tariffs in water use [6,15]. Ref. [16] focus on the luxury segment examining a five-star hotel in Portugal, explaining the water-saving measures implemented and analyzing how they contribute to differentiate the hotel from its competitors.

Although the research in this field has increased over the years, there are some gaps to be addressed. There is not yet a clear connection among the variables with general frameworks for sustainability such as the SDGs. Some advances can be observed as [17] take a traditional local hotel in Bandung (Indonesia) and analyze the introduction of sustainability strategies as a part of new marketing strategies needed to revitalize the accommodation establishment. In addition, ref. [18] explore the relationship between Corporate Social Responsibility, SDGs performance and financial result. The current study goes a little deeper and makes a first proposal to align the real actions implemented by a hotel to improve its water management with the different topics within the SDGs.

Moreover, there are still contradictory results on the influence of certain factors such as garden area, and more research is needed to confirm those factors where greater consensus has been reached. Additionally, more research is needed on the impact of external factors, especially those related to climate conditions, since only a few studies have delved into this topic [19]. To help close this gap, this study makes an approach through the influence of rainfall and temperature on water consumption in gardens, as they are an important part of the total water use in the hotel.

Regarding the use of case studies, ref. [20] suggest improving the method for more theory development. This gap is addressed by the studies conducted by [21,22] which focus on one single establishment which was used to build a framework to characterize water consumption in hotels. On the same path, this paper aims to enhance the existing framework in this area using a comprehensive case study, thereby addressing several gaps present in the current literature as explained above.

To achieve that, an analysis of water consumption determinants in a hotel in the island of Tenerife, Spain, which is internationally recognized for its good practices and has received numerous awards over the years, will be carried out. The results might be valuable both to strengthen existing research and to highlight contradictions between academic findings and practical applications of water management that can lead to the reformulation of the framework.

To better structure the research, three research questions were enounced:

• How do the hotel’s water management actions align with the SDGs? This research question addresses the gap detected above and can be useful in terms of communication with the stakeholders.
• What are the determinants of water consumption in the hotel? It can help to confirm previous results or decide whether to open new lines of research if contradictory findings are found.
• How do weather conditions affect water consumption in gardens? The answer to this question can help enlarge the knowledge on the influence of external factors on water consumption. In this case, it has been limited to gardens, since it is a facility where many measures have been implemented and their surface has remained stable during the analyzed period.

After this introduction, a brief review of the literature on the topic is made, focusing on the determinants related to water use in the hotel sector, aiming to build a scheme that reflects which variables have been studied and how they influence water consumption. The Section 3 focuses on the description of the case study and its water-saving measures. The Section 4 shows the methodology used, building the above-mentioned scheme and the variables considered to analyze the hotel’s performance and the influence of the measures introduced. Following this, the results of the analysis are provided and compared with theoretical schemes extracted from the literature. Finally, the discussion and conclusions are presented, and the limitations and future lines of research are explained.

2. Determinants of Water Consumption in Hotels

The need to efficiently manage water resources in tourism justifies the research efforts to analyze the variables that influence water consumption in tourist accommodation establishments. To build an explanatory framework of the variables conditioning water consumption in hotels according to the existing literature, the above-mentioned work of [12], who conduct a systematic literature review of the field of the period of 2000–2019, can be a useful starting point. This review identified eleven articles on the topic of significant variables in hotel water consumption, and more studies can be found from 2020.

According to that literature review, the existing research on the topic has almost exclusively used quantitative methods with few examples of qualitative methods such as interviews or other kinds of analysis. This opens the question about the influence of factors that cannot be measured through the collection of information from hotels, such as perception of guests, proactivity of managers or external factors like influence of sustainability policies, or legal framework in general.

To advance in this path, ref. [23] introduce the concept of “green price” that does not refer exclusively to water management but considers the actions within it to measure the intention of tourists of visiting green hotels in Malaysia. In addition, ref. [24] make a proposal to measure the impact of green practices, including information about water-saving measures and the application of those in customers satisfaction for floating hotels in Luxor.

The variables obtained from different studies on water resources in the hotel industry can be divided into four main groups: physical (or general) characteristics of the hotel, water-related units, hotel occupancy, and variables related to the system of hotel management [13,25].

As dependent variables, almost all the articles used two indicators either individually or jointly: total water consumption during a specific period of time, usually one year [9,26] or water consumption per guest night (also called “per tourist per day”) [13,14,27,28] Some articles use both [10,19,29] and others use different variables such as consumption per room and months open [30] or monthly consumption per bed [15]. In most cases, the variables used in the study depend on the availability of data that hotels can provide, which is also the case of this study. Once the theoretical scheme is built, total water consumption and consumption per guest night will be the basis to assess the effect of the defined independent variables.

2.1. General Characteristics of the Hotel

Hotel’s physical characteristics can be addressed through different aspects. One of the most frequent is hotel size measured in number of rooms [9,26,31] or beds [4,10]. For total water consumption, [7,9,26] show that hotel size has a significant effect on total hotel water use (direct relationship). However, the relationship between the hotel size and water consumption per guest night identified by research is somewhat ambiguous. Thus, according to [19], a 10% increment in the number of hotel rooms increase water use per guest night by 12 L in the hotels of several Asia-Pacific countries. Conversely, [9,13] prove that in Spanish hotel establishments, it seems that large hotels have lower consumption per guest night. This discordance could be explained by differences in the geographical areas of the hotels, different tourist profiles, etc. In the work of [6], the dependent variable is annual hotel water consumption per room and month open. In this study, the relationship with hotel size measured in the number of rooms is inverse. According to the authors, an increase in the quantity of hotel rooms leads to a rise in overall water usage, yet it diminishes the dependent variable due to the distribution of community consumption among a larger number of rooms.

Another variable that can be addressed to this group is the floor area of the hotel. Ref. [13] find it a significant factor for explaining daily water usage per guest in the mass sun-and-sand tourist destination of Lloret de Mar, Spain: per each additional m² of floor area, water consumption increases by 0.311 × 10⁻³ L per guest night. As for total water consumption, according to [32], for Scandic hotels total floor area is a determining factor as consumption increases by 0.376 m³ for each m². Ref. [8] estimate that an increase of 1% in the total area of the accommodation in a resort of Kazakhstan results in an increase of 0.301% on the total water consumption.

The effect of the hotel’s number of stars on water consumption has also been analyzed by many studies. In the research of [7], data on annual water consumption has shown that higher category hotels consume more water annually than lower category hotels. In the above-mentioned study, ref. [13] do not study the difference between hotel categories, but the distinction in daily water consumption per guest between hotels with and without stars, and also find this influence on water use significant. According to the authors, hotel establishments without stars use less water than those with stars, possibly because they have fewer facilities that need water.

2.2. Water-Related Units

Water-related units include all hotel facilities that require water: restaurants, kitchen, swimming pools, gardens, spa, and others. Most commonly, existing research uses these units in one of two ways. First, they are used to characterize water-related facilities and their capacity/area. For instance, ref. [13] analyze the number of dishwashers. The results obtained show they are significant for the water consumption per guest night by increasing it. Their model also shows that the amount of water used per guest night decreases substantially with increasing outdoor pool volume. Another important factor influencing water consumption is one related to restaurants and number of food covers served [32,33]. According to [32], each food cover sold in hotels consumes an additional 6 L.

A facility of great importance is the garden area. However, the results on this variable are contradictory. Some authors like [14] consider irrigated gardens as one of the main water-consuming factors. Ref. [32] state that if the hotel has grounds that require irrigation, each m² of landscaped ground area consumes 0.088 m³ of water per year. [31] confirm that the larger the area, the higher the water demand. Regarding water consumption per guest night, refs. [13,34] find that lawn size is a non-significant variable.

Laundry service may consume up to 30% of water if this facility is in-house [35]. According to [36], the existence of in-house laundry strongly affects total water use in hotels. Nevertheless, ref. [34] find that this relationship with water consumption per guest night to be non-significant, which is confirmed by the study of [13].

The most common way to measure the influence of water-related units is to use them in a water consumption model as dichotomous variables, where 1 means the presence of this facility and 0 means the absence. Refs. [9,26] find that golf courses and swimming pools (in the case of the latter—the number of swimming pools) have significant effects (direct relationships) on the total hotel water consumption. The existence of a spa in hotels does not always show a significant effect, such as in the study by [9], that confirms the results obtained by [32]. In addition, an inverse relationship is found between hotel water consumption per room, months open, and the existence of spas in the research of [30]. The authors explain that this effect is because spa activities may substitute water consumption in hotel rooms, thus reducing it.

2.3. Hotel Management

One of the most frequent variables whose influence is being studied in the hotel sector is the introduction of water-saving measures. Some authors analyze the relationship between a specific measure and water consumption, others study it between the whole set of these actions and water use. For instance, ref. [37] estimate that installing new fittings with an aerator in taps and showerheads in guestrooms reduces water consumption by up to half. [13] find that having an environmental and/or quality certification has a significant effect on reducing water consumption rates per guest night. Ref. [19] also compare hotels and their water practices across several Asia-Pacific countries and discovered that an increase of 10% of low/dual-flush toilet installation in hotels reduced water use by 3 L per guest night. Ref. [38] evaluate the impact of retrofitting measures on a hotel’s water consumption. According to the results, introducing water-saving devices on the taps of hotel bedrooms and public areas (such as aerators and flow restrictors), together with replacing taps and dishwashing stations in the kitchen with more efficient ones, leads to a 21.5% reduction in annual water consumption.

Ref. [9] introduce water-saving initiatives as a dummy variable and prove that hotels applying these initiatives could reduce their annual average consumption by up to 13.6%. According to [30], the introduction of water-saving initiatives in hotel companies (like reusing swimming pool water, recycling sewage for irrigation purposes, installing water-saving devices in hotel bathrooms, etc.) is effective in reducing water consumption. Ref. [7] analyze the technical and organizational water-saving measures adopted by the hotels in Barcelona, Spain. It was noted that the years with higher adoption rates of water conservation measures also matched the years in which a larger reduction in water consumption was observed. Consequently, there is a broad consensus about the positive influence of introducing water-saving initiatives and measures to reduce water consumption.

In addition to private water-saving measures, several studies have explored the role of public sector actions by analyzing the influence of water tariffs and their structure on water use [6,15,30]. More specifically, ref. [30] investigate the relationship between water tariff structures and hotel water consumption on the island of Mallorca, Spain. The authors discovered that different water-pricing structures are not linked to water use in the hotel sector of Mallorca. Ref. [26] also explain that the absence of a relationship may be because the cost of water is relatively small compared to the overall operational costs of a hotel, thus reducing its influence on hotel water use.

Chain affiliation is another variable that influences hotel water consumption. For analysis, this variable is divided into two groups: hotels that belong to a hotel chain and independently operated establishments, in some cases dividing chains into small, medium, and large. A consensus is still to be reached on this variable. According to [13], independently operated hotels consume less water per guest than affiliated hotels. Nevertheless, ref. [9] observe that hotels belonging to small chains usually display significantly lower water consumption levels than independent hotels, while those affiliated to big international ones usually present higher levels. Ref. [30] explain that belonging to a chain probably facilitates the introduction of efficient processes in water management. By contrast, those hotels belonging to large chains (with hotels located worldwide) are related to higher levels of water consumption as water costs account for an insignificant share of hotel operational costs, thus reducing the importance of introducing water-saving measures.

Some research includes the number of employees of the hotel as a possible variable that can affect hotel water consumption. For example, ref. [39] find that this variable significantly affects the daily water consumption per guest in the hotel industry.

Finally, another important variable to mention here is the type of board used in hotels ranging from “accommodation only” to “all-inclusive”. Following [9,40], an increase in the number of boards that the hotel offers produces a significant increment on total annual water consumption but also in water consumption by guest both directly, due to higher water consumption, and indirectly, due to more water use to prepare the meals.

2.4. Occupancy

This group includes aspects related to continuously changing characteristics such as occupation level and number of guests. Ref. [9] observe the occupancy rate of the hotel sector of Mallorca, Spain, to be a key explanatory variable in hotel water consumption, since the more guests a hotel has staying in its rooms and using its facilities, the higher the water consumption. Nevertheless, as the authors discovered, the average annual occupancy rate does not affect total water consumption. The result of the study of [8] also reveal that there is no significant effect of annual average occupancy level on total water consumption. However, analyzing the effect of the occupancy on water consumption per tourist per day, ref. [14] indicate in their study that higher occupation rates reduce this water consumption. This is logical because with higher occupancy, fixed water consumption in facilities such as pools or gardens is divided among more guests. The study of [22] also confirms the pattern.

Moreover, hotels in Asia-Pacific countries demonstrate a direct significant link between the number of guest nights and total water use [19,32] provide a better understanding of the key factors determining water consumption in Hilton International and Scandic hotels in 24 European countries that included all the existing climate zones. The authors showed that for the mid-market brand, guest nights sold was by far the most influential variable for total annual water consumption with each additional guest consuming 0.165 m³ of water. In the case of water consumption per guest night, the authors calculate that if guest nights increase by 10%, average water use decreases from 399 L to 387 L per guest night.

2.5. Other Factors

In addition to the above-mentioned aspects, there are some variables external to the hotel that have been researched. For example, some authors have studied climate conditions and geographical areas for their influence on water consumption in the hotel sector. Ref. [19] find that the climate zone in which the hotel is located significantly affects total and per guest night water use in hotels of Asia-Pacific countries. [14] showed that geographical location and environmental and/or climate conditions define some of the main water-consuming factors, such as irrigated gardens, swimming pools, spa, and others. As an exception, ref. [32] do not find water consumption in hotels highly dependent on weather conditions. Despite this latter result, according to most authors, there seems to be a significant influence of climate conditions on water consumption in hotels.

Research on the behavior of hotel guests and how this affects water consumption takes an important place in the literature, since in-room water use, which depends directly on guests, occupies a high share of total consumption in hotels, reaching 42% of total consumption [41]. Thus, ref. [27] examine the underlying motives of tourists’ in-room water conservation behavior in a leisure tourist destination of Benidorm, Spain, and highlighted the importance of hedonic motives (personal comfort and enjoyment) for this behavior.

3. Hotel Tigaiga: Environmental Management as a Competitive Advantage

The Hotel Tigaiga (Tigaiga, S.A.) located in the north of the island of Tenerife, Canary Islands, Spain, has been selected as a case study in this paper. There are two main reasons for selecting this establishment. First, the study of [42] shows that environmental sustainability is one of the factors recognized by several stakeholders as a part of the social value of the Hotel Tigaiga. The promotion of those practices, in addition to improving water consumption, has been demonstrated to positively impact the image of the hotel and in the loyalty of the customers [43]. And second, the Hotel Tigaiga is in the municipality of Puerto de la Cruz, one of the most touristic areas of Tenerife. Tenerife is a popular destination that receives more than 5 million tourists annually [44]. This means that a great amount of water goes to the tourism sector and hotels are one of the main consumers [22].

General Characteristics of the Hotel

The four-star Hotel Tigaiga is a family business founded in 1959 by Enrique Talg Schulz and his son Enrique Talg Wyss. Its sustainability reports are public and give general information about the establishment as well as the actions that have taken place on it. The hotel has a total of 83 rooms, of which seven are junior suites, spread over four floors, with a total capacity of 166 beds and a total area of 10,008 m². This accommodation establishment also has two restaurants, a kitchen, laundry service (external dry cleaning), meeting rooms, gardens, swimming pool, sauna, and sports rooms. The pool is heated all year-round taking advantage of energy from solar panels. In 2007, the area of the gardens was increased by 3000 m² and nowadays is 8730 m² in size. When the hotel was designed, subtropical vegetation was planted, however, over the years, it decided to incorporate native Canary Islands species that adapt better to the climate and need less water. Also, the pool was built in 1963 with a rectangular shape and a depth from 1.20 to 2.70 m, so the volume of water it needs is high. The hotel is currently considering undertaking a project consisting of reducing depth in the pool. Also, the hotel has numerous quality certifications and has been awarded for its effective social, environmental, and economic impact in hotel management.

The Hotel Tigaiga has maintained an environmental management policy, where it is worth highlighting its efforts and concerns to develop a rational management of water resources. As evidenced in most published papers on this subject, concern for water resource efficient management in accommodation establishments normally forms part of a broader package of environmental management measures [45,46,47,48].

Annually, the Hotel Tigaiga analyses its environmental performance, distinguishing between direct environmental aspects (water consumption, energy consumption, atmospheric emissions, noise levels, wastewater generation, waste generation, and the hotel’s environmental actions) and indirect environmental aspects, related to its guests, suppliers, and contractors’ behavior. Based on this analysis, it sets specific environmental objectives each year, which has allowed it to maintain a process of continuous improvement that has become a hallmark of the hotel.

4. Methodology

For this case study, to classify the hotel’s water management measures into the SDGs business themes, the environmental statements prepared by the Hotel Tigaiga from 2007 to 2020 have been analyzed, and several qualitative interviews were conducted with the quality manager at the hotel.

For the quantitative part, based on the literature review, a theoretical scheme can be built, where variables were divided into five groups, showing the factors influencing water consumption in hotels and their expected relationship with both dependent variables according to previous research.

Table 1. Determinants of hotel water consumption according to the previous literature.

Independent Variables		Expected Sign over Total Annual Water Consumption	Expected Sign over Water Consumption per Guest Night
Groups	Determinants
Physical characteristics of the hotel	Hotel size	Positive	No consensus
	Floor area	Positive	Positive
	Number of starts	Positive	Positive
Water-related units	Pools	Positive	Positive
	Spa	No significant	Negative *
	Golf courses	Positive	Unexplored
	Laundry service	Positive	Non-significant
	Garden’s area	Positive	Non-significant
Hotel management	Water-saving measures	Negative	Negative
	Water tariff	Non-significant	Non-significant
	Chain affiliation	No consensus	No consensus
	Number of employees	Unexplored	Positive
	Type of board	Positive	Unexplored
Occupancy	Occupancy rate	Non-significant	Negative
	Number of guest nights	Positive	Negative
Other variables	Climate conditions	Significant	Significant
	Guests’ behavior	Significant	Significant

Notes: * In this case, the study of [30] refers to water consumption per room and months open, which can be considered similar to water consumption per guest and night. Source: Prepared by authors.

indicates for each independent variable if: (a) it has been found significant and if the expected sign of the relationship is positive or negative; (b) it has been found non-significant; (c) there are contradictory results from previous studies and, therefore, no consensus has been reached about their influence on water consumption in hotels; or (d) the relationship has been unexplored.

According to the previous literature analyzed, there is no consensus about hotel size and chain affiliation. In most cases, the independent variable has the same expected sign with both dependent variables. Some exceptions can be found for the number of guest nights, gardens’ area, and in the presence of spa. Occupancy rate was not found to be significant for total water consumption but has a positive correlation with water consumption per room and months open. Regarding climate conditions, the existing literature has found its influence over water consumption significant. However, no analyses were found regarding the influence of specific variables such as rainfall and temperature on total water consumption and per guest night, although the effect of rainfall was examined in relation with golf courses in the study of [26]. Finally, some relationships are still unexplored such as the influence of the number of employees on total water use and the type of board and existence of golf courses with consumption per guest night.

Once the framework has been established, it will be examined whether the Hotel Tigaiga follows this general pattern. To do so, data corresponding to different variables from 2007 to 2019 were considered and a statistical analysis was performed to evaluate the variables’ behavior in this period. It is important to note that data until 2019 were used as from 2020 the situation could not be analyzed properly due to the pandemic. From the possible variables to be examined, some of them such as general characteristics and water-related units will not be considered as they were constant during the analyzed period. In addition, there are some possible variables previously used in the literature for which data were not available from the hotel. Thus, as shown in Figure 1, the study includes variables that have changed in the period of the study, have been proven to be significant at least for one dependent variable by other studies, and where data was available. In the case of climate conditions, two independent variables have been introduced: average rainfall, whose relationship with the dependent variables is expected to be negative due to theoretical saving of water for gardens’ watering; and average temperature, which is expected to have a positive relationship since hotter seasons normally lead to higher water consumption. As for the water-saving measures, substitution of taps and comprehensive renovation of rooms were chosen because they were implemented in three years between 2007 and 2019. Figure 1 presents the methodological framework and indicates whether the literature established that the expected sign of the correlation is positive (+), negative (−) or the variable has been found non-significant (NS).

For modelling water consumption in the Hotel Tigaiga and answering the second and third research questions, bivariate correlations were used. These methods belong to the so-called “first generation” methods [49] (p. 1). Regardless the presence of some limitations for using these types of correlations such as the simplicity of the models resulting, the need of observation of all variables at the same time, and the requirement of absence of measurement errors [50], the data used in this study are suitable for applying this method.

To answer the second research question, total water consumption and water consumption per guest night were defined as dependent variables, while the other available indicators were used as independent factors. For the third question, water consumption in gardens was the dependent variable and weather conditions the independent one.

5. Results

5.1. Hotel Water Management and the SDGs

A list of the measures related to water management implemented by the Hotel Tigaiga during this period is presented in

Table 2. Specific measures focused on water saving adopted by the Hotel Tigaiga from 2007 to 2020.

Business Theme	Action	Location	Year (s) of Implementation
Water saving—water saving technologies and awareness campaign	Substitution of traditional taps for single handle taps in rooms	Rooms	2007, 2010, 2015
	Comprehensive renovation in rooms including new bathrooms and water-saving showers installed, elimination of bathtubs and bidets. The circulation of hot water is improved so that it reaches sinks and showers faster.	Rooms	2012, 2014, 2015
	Installation in showers of manual timer button.	Pools	2010
	Expansion of automatic irrigation in gardens with specific control of irrigation schedules and night irrigation.	Gardens	2007
	Automated drip irrigation in the hotel’s garden area.	Gardens	2012
	Use of pine splinter as mulch for plants, to reduce water evaporation.	Gardens	2014
	Buying machinery to clean the terraces.	Gardens	2019
	Use of compost to favor the retention of water.	Gardens	2017
	Training for workers on the rational use of water.	Management	2017, 2020
Water savings—Reduce the water footprint	Purchase of new furniture for the outdoor terrace, which makes it possible to dispense with the washing of furniture linen.	Laundry	2007
	Analysis of watering needs of the new plants introduced.	Gardens	2017, 2020
	Review of garden watering schedules.	Gardens	2019
	Substitution of tablecloths for more sustainable materials to avoid laundry.	Restaurant	2019
Water efficiency—reduction in volume consumed	Installation of a new cleaning system with the Speactank deposit to reduce water consumption.	Kitchen	2007
Water consumption—location of specific data	Installation of a new water meter.	Entrance of the hotel	2008
	Construction of a new placement for consumption and irrigation water meters.	Gardens	2014

Notes: source prepared by authors from the environmental declarations of the Hotel Tigaiga and the document on Business Reporting of the SDGs from [51].

. To answer the first research question, the guidelines established in the document on Business Reporting of the SDGs from [51] were used. The results showed that the actions can be linked to Target 6.4, aimed at increasing the efficient use of water resources. Therefore, each of the measures carried out by the Hotel Tigaiga has been allocated to a business theme as described by the guide. This can provide an initial overview of the contributions of the measures implemented to Goal 6 of the SDGs and can serve as a guideline for this and other hotels to improve their strategies and communication.

Mainly, the hotel has implemented water-saving measures in rooms and gardens. In the case of the rooms, the actions included the introduction of new features that allowed a more efficient use of water, such as single handle taps, controlled discharged mechanism and the elimination of bathtubs and bidets. For the gardens, the measures are focused on different aspects and include not only the automatization of irrigation but also actions that are the result of a process of reflection by the hotel management to change long-term habits regarding watering schedules or the type of plants used. The attention paid to the garden area shows the importance that is given to this part, which constitutes a distinctive feature of the hotel and has become a point of attraction for tourists and locals.

It is also remarkable that the introduction of water-saving measures has been constant during the period analyzed. The hotel has kept modifying both its processes and physical characteristics to achieve more water efficiency. Especially noteworthy is the period from 2012 to 2015, where practically all the rooms were refurbished, causing the closure of the hotel during some months in those years. It shows the environmental commitment of the hotel, which carried out such expensive actions in the context of an economic crisis.

The next step to evaluating whether the variables in the Hotel Tigaiga follow the expected path was to offer a general overview of the evolution of the variables over the years, as is shown in

Table 3. Evolution of variables in the Hotel Tigaiga in 2007–2019.

Variables	2007	2008	2009	2010	2011	2012	2013	2014	2015	2016	2017	2018	2019
Total water consumption, m3	14,563	15,231	13,965	13,554	13,481	16,311	16,108	16,443	17,041	15,374	15,848	15,360	15,694
Consumption per guest night, L	433	416	366	361	267	330	369	330	401	288	305	315	355
Consumption per guest night (without gardens), L	291	276	252	243	189	244	272	235	265	195	193	213	260
Occupancy rate, %	55.51	60.44	63.00	62.05	83.44	81.50	72.14	82.34	70.23	88.17	85.90	80.50	72.96
Number of guest nights	33,633	36,620	38,172	37,594	50,555	49,383	43,712	49,887	42,551	53,423	52,045	48,774	44,205
Water-saving measures: Substitutions of taps	1	0	0	1	0	0	0	0	1	0	0	0	0
Comprehensive renovations in rooms	1	0	0	0	0	0	0	1	1	0	0	0	0
Average temperature, °C	20.70	20.85	20.78	21.16	20.90	21.27	21.11	20.84	21.31	21.02	21.84	20.71	21.17
Average rainfall, mm	193	155.8	366.8	228.8	273.2	494.8	203.04	477.6	191.5	295	77.3	329.7	224.8
Gardens’ data
Garden area, m2	8730	8730	8730	8730	8730	8730	8730	8730	8730	8730	8730	8730	8730
Consumption in gardens, m3	4758	5138	4706	4766	4195	4619	4550	4619	5060	4948	5640	4905	4152
Consumption in gardens, L/m2	550	594	544	551	485	534	526	534	585	572	652	567	480
Garden consumption, % of the total	32.7	33.7	33.7	35.2	31.1	28.3	28.2	28.1	29.7	32.2	35.6	31.9	26.5

Notes: source prepared by authors from the information published in the environmental statements of the Hotel Tigaiga.

.

After that, the behavior of the dependent variables was analyzed, and bivariate correlations were performed to determine the significant factors affecting both total water consumption and consumption per guest night. Finally, water consumption in gardens and the influence of weather conditions were assessed separately.

5.2. Water Consumption in the Hotel Tigaiga

The behavior of the total water consumption and water consumption per guest night, which have been generally considered as dependent variables in the existing literature, were analyzed first. As shown in Table 3, an increase in total water consumption was observed in the years 2008 and 2012–2015. For 2008, this could be explained due to the addition of 3000 m² of new garden areas that started in 2006 and produced a greater need for water for irrigation. Between 2012 and 2015 it was a particularly hot period, which could have resulted in higher water consumption.

For the second variable, water consumption per guest night, a similar process has been conducted. Water irrigation does not exert a noticeable influence on water consumption per guest night. The data were calculated with and without garden consumption following a similar path from 2007 to 2019 (Figure 2).

There is a noticeable increase in water consumption per guest night in 2013 and 2015 despite efforts to improve efficiency in the management of this resource. In this period, in addition to the unusual temperatures, the hotel remained closed for several weeks in the summer months due to renovation work, specifically at the entrance, in common areas, and in rooms. It should be noted that most of the hotel’s guests normally come in winter and, therefore, the summer months were selected for the building work. By not hosting guests during this period, water consumption was only related to the renovation work, therefore the results obtained, as shown in the environmental statements of the corresponding years, were atypical.

5.3. Which Are the Determinants of Water Consumption in the Hotel?

After an initial overview, a deeper analysis of water consumption in the Hotel Tigaiga was performed to answer the second research question. Following the example of [52] for the case of energy and water consumption in a similar destination (Lanzarote, also an island of the Canary archipelago), the correlations between dependent and independent variables were examined individually, as shown in

Table 4. Bivariate correlations coefficients between dependent and independent variables.

	Dependent Variables	Correlation with Total Annual Water Consumption	Correlation with Water Consumption per Guest Night
Independent Variables
Occupancy rate		−0.143	−0.889 *
Number of guest nights		−0.143	−0.889 *
Water-saving measures:
- Substitution of taps		0.102	0.568 *
- Comprehensive renovations in rooms		0.227	0.449 *
Average temperature		0.222	−0.215
Average rainfall		0.018	−0.305

Note: * Coefficient resulted significant at 95% confidence level. Source prepared by authors.

. For the analysis, PSPP 1.6.2 software was used, a statistical open-source software that has been used in the field of tourism by [53]. The findings obtained can be used to the relationships shown in Figure 1. To determine significance, a 95% confidence level was used and those coefficients which were found to be significant are indicated in the table with an asterisk.

Looking at the correlation coefficients obtained for total water consumption, the variable of average temperature follows the expected sign expressed above but does not show significance. Similarly, both occupancy rate and the number of guest nights was found to be non-significant, which was already found by [9]. This would imply that fixed consumption has a bigger impact than the variation on the number of guests.

Regarding the introduction of water-saving measures, it seems they had no significant effect on total water consumption, which contradicts previous studies, for example [7], who establish that these measures help diminish water use in hotels but pointed out the possible influence of hotel category. This poses the question of how other factors might harm the expected reduction in total water consumption and might discourage the hotel to introduce further measures if they do not provide the desired effect. Finally, none of the coefficients related to weather conditions were found to be significant. In the case of temperature, the positive coefficient followed the expected results, but the contrary is true for rainfall, which was expected to be negative.

Similarly, for the case of the consumption per guest night, not all the results were in line with the existing literature. Occupancy rate and the number of guest nights were strongly and negatively correlated and were both significant at the 95% confidence level, which aligns with [19]. There was a positive correlation with the hotel’s renovation measures. The results were contrary to the expected behavior because they showed that the introduction of measures leads to greater water consumption per guest night. One possible explanation is that the effects of the measures on water consumption might depend more on the quality of measures than on their quantity. Measures were considered dichotomous variables, which took the value 1 in those years they were introduced and 0 otherwise; hence, the effect of the increase in quality was not evaluated.

Therefore, we can highlight the existence of a counterintuitive effect that increases water consumption because customers now feel more comfortable and, for example, with better bathrooms they might take longer showers. This would be consistent with the existing literature that relates better services with higher water consumption [10]. Lastly, and opposite to the relationship with the other dependent variable, a negative correlation was observed with both temperature, which follows the expected results, and with rainfall, which is the opposite of the predicted result.

Regarding both dependent variables, the differences compared with the forecasted results could be due to the existence of multicollinearity between the variables, which could lead to a bias in the estimation of coefficients [54].

5.4. How Do Weather Conditions Affect Water Consumption in Gardens?

To address the third research question, the study on how weather conditions might affect water consumption in gardens was carried out. Since the garden area changed in the first year of the analyzed period, it was not possible to consider this variable in the correlation analysis. However, it is important to note that the Hotel Tigaiga calculates the indicator of water consumed per m² in gardens due to several reasons: gardens represent 30–35% of water used, their area grew almost 50% in 2007, and many water-saving measures have been implemented there. Therefore, the theoretically positive effect of these measures could be questioned looking at the data of Table 3 about gardens’ water consumption, which did not show a clear reduction. Therefore, it is relevant to study the effect that weather conditions have on them, since they can also help us understand how, despite the hotel’s good environmental policies, external factors can influence water consumption in this area. The amount consumed in the gardens between 2007 and 2019 and the average temperature and rainfall during those years are presented in Figure 3.

The consumption of water by m² of garden ranged between 480 and 652 L from 2007 to 2019. Starting from 2015, the consumption per m² decreases, which can be due to extension of automatic irrigation with specific control of irrigation schedules and night irrigation. However, Figure 3 itself does not show a clear effect of neither the rainfall nor average temperature on water consumption in gardens, except for the extreme case of 2017. The sharp increase that led the indicator to the highest value of the series can be linked to the rare weather conditions that year. According to the State Meteorological Agency [55] in Puerto de la Cruz, 2017 was one of the warmest and driest years of the 21st century exceeding the values of 2014 and 2015. This circumstance explains the increase in the water used for garden irrigation in that year.

To clarify the influence of weather conditions on water consumption in gardens, the correlation coefficients between variables can be examined, taking gardens’ consumption as the dependent variable. The results are shown in

Table 5. Bivariate correlation of garden water consumption, average temperature, and rainfall.

Variables Compared	Correlation Coefficients
Garden consumption (L/m2)/average temperature (°C)	0.444
Garden consumption (L/m2)/average rainfall (mm.)	−0.437

Note: source prepared by authors, the significance is established at 95% confidence level.

.

The results followed the expected path described in the methodological part. Although none of them are significant at 95% confidence, they are at the 85% level. Thus, it is expected that a higher average temperature will lead to higher garden water consumption whereas the opposite is true for average rainfall. This could partially explain why the introduction of water-saving measures in gardens did not result in the expected effect of reducing water consumption. The influence of harsh weather conditions during the period considered can counterbalance the reduction in water consumption that should derive from the implementation of measures.

6. Discussion and Conclusions

In this study, the literature on factors affecting water consumption in the hotel sector was reviewed and a framework has been proposed summarizing how different authors have characterized individual relationships between consumption variables. The resulting framework has been applied to a case study of a hotel internationally recognized for its good practices in water management to evaluate if the behavior of water consumption followed what has been established before. The use of a single case study is justified in the unique characteristics of the hotel, and it allows for the easy addition of qualitative information [56]. The findings for the consumption showed that, with few exceptions, the sign of the relationship between the independent variables and total and per guest night water consumption agreed with the previous literature in the field. However, for total water consumption, the relationships are more unclear and can be influenced by the presence of multicollinearity.

6.1. Theoretical Implications

The answer to the question about which variables influence water consumption in hotels, in addition to confirming previous research, might open new enquiries and can shed light on aspects of the literature that are still unclear. Thus, to quantify the effect of water-saving measures, the specific characteristics of those implemented must be considered. In this case, the increase in quality brought by the renovation of rooms might have had an undesirable effect on water consumption because it increased the comfort of customers. Therefore, additional variables focused on guests’ behavior should be added. Regarding to the third research question about how external variables might influence garden water consumption, the results are on the intuitive path in which higher average temperatures lead to greater water demand for gardens, with the opposite being true for higher rainfall. These outcomes cannot be directly extrapolated to other hotels, since the nature of the gardens and other weather conditions could influence water consumption, but this is a first step for building a more consistent theoretical and practical framework.

6.2. Practical Implications

The policy of continuous improvement adopted by the Hotel Tigaiga, in relation to optimal water resource management, has led to significant savings in water consumption per guest night. This adds to the evidence from other studies carried out in this line that encourage efforts in terms of efficient management of water resources in the hotel environment [57]. In general, it appears that after the efforts made, the Hotel Tigaiga is in line to meet the objective proposed in the Sector Reference Document on the best environmental management practices for various sector (including tourism) that was elaborated by [58]. In this the sectoral indicators of environmental behavior and the comparative parameters of excellence for the tourism sector are developed. This document establishes a limit of total water consumption less than or equal to 140 L per guest night in fully serviced hotels. Therefore, considering the characteristics of the hotel under study, with constant operation, high occupancy, services open throughout the year, swimming pool, etc., the consumption achieved in the last year studied (2019) is still far from the level set out by the Sector Reference Document.

The hotel has introduced a great number of water-saving measures, but they do not always clearly affect total and per guest night water consumption, which could be due to the influence of other variables such as climate, for example. This should not discourage hotels from introducing those measures, because they most probably help diminish the negative effect of external factors on water consumption. This information would be useful for hotels that introduce water-saving measures to have a more precise understanding of their actual effect over time.

Aligning the water-saving measures according to the business themes of the SDGs could also help hotels better communicate their efforts to improve their water management in alignment with an internationally recognized framework. From the academic perspective, it opens a field for future research that could help connect the emerging literature on the SDGs and water management following the work of [12]. In the case of the Hotel Tigaiga, most of the actions can be classified as water-saving technologies and the reduction in water footprint.

6.3. Limitations

This research presents several limitations and avenues for future research. First, panel data from other hotels in the same destination could clarify the effect of multicollinearity within the independent variables. Second, some possible variables that could be included did not have available data. Third, a more qualitative study of the effect of the measures would enrich the findings obtained. To refine the management associated with water resources, it would also be essential to have information on water consumption for each service (rooms, kitchen, laundry, swimming pool, gardens, etc.).