Coping Strategies to Address Water Scarcity through Local Knowledge in Tidal Flood and Erosion-Prone Areas: A Case Study of Timbulsloko, Sayung Regency, Demak Municipality

Access to clean water in Indonesian households remains relatively low due to insufficient clean water facilities and infrastructure. This research addresses the Sustainable Development Goal (SDG) of providing clean water, sanitation, and a clean environment (abbreviated as WASH) in sinkingcoastal areas vulnerable to tidal floods and erosion. PDAM and PAMSIMAS services struggle to function effectively in these regions. Despite government programs aimed at providing drinking water to impoverished communities, PDAM services often remain inaccessible to residents in subsiding coastal areas afflicted by floods, tides, and erosion. The residents of Hamlet Timbulsloko face a critical challenge in securing clean water and maintaining proper sanitation, exacerbated by submerged wellscaused by erosion. In their quest to meet this basic need, residents have adopted various coping strategies, including rainwater collection using buckets, basins, and even repurposed containers. Rainwater harvesting has become a community-driven solution to the unmet need for clean water, particularly when the cost of refill water is prohibitively high within the region. This research takes inspiration from the local knowledge and practices of residents and seeks to provide a rainwater harvesting model as a sustainable clean water solution


Introduction
Sayung is a sub-district located in the northern part of Demak Regency.Several studies have revealed that the Sayung coastal area is highly susceptible to hydrometeorological disasters such as flooding, erosion, tidal flooding, and land subsidence.These hydrometeorological disasters have placed the population residing in the Sayung coastal area in challenging living conditions, particularly regarding the provision of clean water for bathing, washing, and toilet (MCK) purposes.
To date, the coverage of piped drinking water services provided by the Regional Drinking Water Company (PDAM) has not been distributed evenly.Clean water needs in coastal Sayung areas that remain unreachedby PDAM services are typically met through well water.This includes shallow wells owned by households and communal boreholes, with an average depth of 120 meters.The vulnerability to land subsidence, tidal flooding, and erosion significantly impacts the water quality of coastal wells.As the Sayung area experiences industrial growth and population increase, the quality and quantity of water from boreholes in coastal Sayung have been diminishing.The volume of water drawn from some wells can no longer meet the residents' needs, necessitating the drilling of new wells.However, both the water from the existing and new wells have become cloudy and have a slightly salty taste.
The combination of meteorological disasters and the challenge of accessing clean water has compelled residents to adapt to their environment.Residents employ various methods to cope with their water sources.Some residents allocate extra funds to purchase bottled water and refilled containers, a substantial burden for coastal residents, particularly considering that accessing clean water through PDAM services and wells already incurs expenses.
The practical and appropriate responses of affected individuals to disasters are closely tied to their knowledge and prior experiences with these challenges [1], [2], [3].Responses are often shaped by their understanding and familiarity with these problems [4].These two factors become even more critical for affected individuals, especially in the context of long-term disasters, where responses can vary over different time periods [4].The willingness to respond, the economic capacity of affected individuals to respond, and the effectiveness of adaptation strategies are factors influencing the types and frequencies of responses.The problems encountered, the impacts experienced, and the responses of affected individuals may differ oralign among them.Thus, it is essential to comprehend the challenges faced by coastal residents living amidst or alongside water bodies.This research aims to bridge the existing knowledge gap in the study of long-term disasters by presenting examples from two localities, one urban and one rural, affected by the protractedprocesses and impacts of land subsidence and coastal inundation.

Methods
The coastal areas of Demak Regency have encountered a range of environmental challenges and disasters.Both regions have experienced land subsidence at a maximum rate of 19 cm per year [5], [6], [7], [8].This land subsidence has resulted in various consequential impacts, including structural damageto buildings and urban infrastructure, increased infiltration of seawater into the land, extensive consequencesof floods and tidal waves, and the emergence of permanently inundated areas [9], [7], [10], [8], [14], [11], [12].These problems stem from two main factors: natural factors and anthropogenic-induced factors, such as significant population growth and large-scale economic activities.
Sayung District in Demak Regency (covering an area of 7,880 Ha with a population density of 13.42 people/ha) also faces substantial environmental challenges and is at risk of various coastal disasters.This situation profoundly influences and impacts the community and economic activities in the area.The total population in Sayung District was 105,712 people [13].In this district, Timbulsloko Village had a population of 3,386 people (with 523 residents in Timbulsloko Hamlet).Meanwhile, Senik Baru was inhabited by 206 families who gradually relocated from Senik Lama since 2005.The majority of the residents in Timbulsloko and Senik Baru are engaged in fishing, farming, and industrial employment.Given their proximity to the sea, these two villages heavily rely on fishing and aquaculture.Furthermore, they are also situated near industrial areas, leading some residents to opt for industrial employment.Several residents in these villages have shifted their livelihoods due to the gradual inundation of their agricultural lands and plantations by seawater, a process that began in 2001 and peaked in 2016 [13].

Data Collection and Analysis
To address the research question, we employed a grounded theory approach.The research methods for comprehending local phenomena included in-depth surveys, extensive interviews, participant observation, and focus group discussions.The research processes and people's perceptions and thoughts were meticulously recorded and documented, including audio and video recordings.In-depth interviews were conducted with key individuals across all research areas.In Demak Regency, affected individuals from different generations and genders, local leaders, spiritual leaders, and local advocates in Timbulsloko and Bedono sub-districts were also interviewed.

Location of Timbulsloko
Hamlet.Timbulsloko village covers 5.96% of the total area of Sayung Municipality.Initially, Timbulsloko Village was not included as a coastal village among the villages on the coast of Kecamatan Sayung.Even the Statistics Bureau office of Demak Regency report for Sayung Sub-district in Figures 2021 (see Table 4.2), does not include the sea boundary at the geographical border of Timbulsloko Village.However, several studies after 2015 noted that Timbulsloko Village has a 4.5 km coastline to the northwest (see Figure 4.2).Based on this research, the geographical boundaries from west to north are Bedono Village, the Java Sea, and Surodadi Village, respectively.The emergence of the coastline and the transformation of Timbulsloko Village into a village bordering the sea is caused by the rising tide of sea water or rob.

Results and Findings
Residents of Timbulsloko Village, including those in Timbulsloko Hamlet, Bogorame Hamlet, Karanggeneng Hamlet, and Wonorejopasir Hamlet, rely on communal wells for access to clean water.These wells were provided by the Demak District Government and are managed under the PAMSIMAS program.Notably, Timbulsloko Village does not fall under the coverage of PDAM services in Demak District.The average cost of obtaining water from PAMSIMAS wells, commonly referred to as "umbul" by residents, ranges from Rp 2,000 to Rp 3,000 per cubic meter.Apart from using water from the umbul for various household purposes such as washing, cooking, and cleaning, the residents of Timbulsloko Village also purchase refill water specifically for drinking.
Among the four hamlets within Timbulsloko Village, Timbulsloko Hamlet faces the most challenging circumstances regarding access to clean water.This section will provide a detailed description of the situation in Hamlet Timbulsloko, which has become isolated from the other three Hamlet within Timbulsloko Village.The physical condition of Hamlet Timbulsloko is progressively deteriorating.All houses in the area have been submerged in water, leading residents to elevate their homes' floors.Residents achieved this by constructing elevated decks and installing wooden floors approximately 1.5 to 2 meters above the original floor level.This construction process resulted in the original PAMSIMAS installation being submerged and rendered nonfunctional, necessitating the creation of a new installation (as shown in Figure 2).After the village became permanently submerged due to tidal floods, residents attempted various methods to access clean water.In 2012, a seawater desalination plant was installed in Hamlet Timbulsloko (refer to Figure 4.10), which residents identified as government assistance.The operation of the plant relies on electricity, the cost of which is covered by selling water to the residents of Timbulsloko Hamlet.Two plastic tanks, each with a capacity of 5,000 liters, were employed to store the desalinated water.According to the residents, the desalinated water produced by the machine can be as fresh as typical freshwater sources.This desalinated water is collected daily in two 5,000-liter plastic tanks.However, the desalination plant's output falls short of meeting the clean water demands of Timbulsloko Hamlet residents.Out of the two saltwater reservoirs totaling 10,000 liters in capacity, only half a reservoir (2,500 liters) of freshwater can be generated.Additionally, this process consumes a significant amount of electrical power, resulting in revenue from water sales to residents failing to cover the operational expenses of the desalination machine.Furthermore, the installation has proven vulnerable to saltwater damage, with both the machine and the protective enclosure succumbing to corrosion.As a result, only the two plastic tanks have been repurposed to store fresh water sourced from the artesian well.However, issues have arisen from within the wells themselves, with the volume of freshwater extracted from these two wells gradually diminishing.This has led to the residents of Hamlet Timbulsloko experiencing an insufficient supply of clean water once again.PAMSIMAS administrators suspect a possible underground pipe leak is causing the decrease in freshwater discharge.If this is indeed the case, repairing such damage would pose a considerable financial challenge.PAMSIMAS managers have recommended that water installations not be buried underground to facilitate easier maintenance.
The declining freshwater discharge from the wells prompted the initiation of a third well drilling operation in mid-2022 (refer to Figure 4).However, this drilling attempt was unsuccessful.The drill bit reached a depth of over 115 meters, but no fresh water emerged.It is noteworthy that the first and third wells are aligned parallel to the former road and river that once divided the Timbulsoko settlement.In light of the failure of the third drilling, a fourth drilling endeavor was initiated in early October 2022, positioned approximately 20 meters south of the third drilling site.By October 10, 2022, it was ascertained that the fourth drilling had reached a depth exceeding 80 meters.Nonetheless, there was no indication of freshwater being released from this location.Since the need for clean water is not met by the two artesian wells, some residents of Hamlet Timulsloko purchase bottled water.There are at least three grocery stalls in Timbulsloko hamlet that sell bottled water.It is not uncommon for residents to buy bottled water with refillable gallons from the neighboring Hamlet, which necessitates the use of a boat, costing between Rp 5,000 -Rp 10,000 one way, depending on the amount of luggage.Stalls selling beverages such as ice syrup and others also utilize refillable bottled water, pricing it at Rp 12,000 per 19-liter gallon package.In addition to purchasing bottled water and refill water, residents of Timbulsloko hamlet also engage in rainwater collection, a practice known as rainwater harvesting, to fulfill their clean water requirements.The harvested rainwater serves a variety of purposes, including watering ornamental plants and vegetables, caring for chickens, washing clothes and utensils, cooking, bathing, hygiene after urination and defecation, and drinking.It's important to note that not all residents or families in Timbulsloko Hamlet utilize rainwater, and not all use it for all of these purposes.
The collection of rainwater intended for culinary and potable purposes does not constitute the initial rainwater harvest following the dry season.The initial rainwater harvest is exclusively reserved for irrigation purposes and is not allocated for any other activities.This distinction arises due to the methodology employed for rainwater harvesting, which involves capturing rainfall through roof tiles, as illustrated in Figure 5 The rainwater harvesting designated for cooking and drinking is not the first rain harvest after the dry season.The initial rain harvest is solely intended for watering plants, without allocation for other activities.This is due to the collection method, which entails gathering rainwater as it descends through the roof tiles of the house (refer to Figure 5).The initial rainfall carries the highest amount of dirt from the roof tiles.As subsequent rains occur and the collected rainwater accumulates, it becomes suitable for various household purposes such as consumption, cooking, drinking, as well as bathing, washing, and toileting activities.Although the amount of dirt carried from the roof tiles diminishes with each subsequent rain, the harvested rainwater undergoes an initial settling process.Typically, residents of Timbulsloko hamlet allow the water to settle for two hours to separate the impurities from the clean water.The resulting clean water is then stored in water gallons, with separate containers designated for drinking water and washing water storage (refer to Figure 6).
In some cases, residents directly consume rainwater collected in the water gallons.However, this practice is not undertaken without careful consideration.One resident conducted an experiment by comparing tap water (refill water) with rainwater stored in the same gallon container.Within two weeks, the refill water containers became contaminated with mold, whereas the rainwater stored in similar containers showed no signs of mold even after one month.The advantages of consuming rainwater for the residents of Timbulsloko hamlet include the following: 1) ease of access during the rainy season; 2) cost-effectiveness, as it does not involve fees based on consumption volume; 3) the taste of rainwater closely resembles that of refill drinking water and bottled water, and in some cases, it is even fresher.Sumber: Survey Primer, 2022

Civic Initiatives in Enhancing WASH Access
Historically, prior to issues of land subsidence, tidal flooding, and coastal erosion affecting the Sayung coast, inhabitants of these coastal regions primarily relied on dug wells (shallow wells) and river water as their sources of clean water.Similarly, Timbulsloko Village originally sourced its clean water from shallow wells and rivers until the aforementioned environmental challenges necessitated a transition to deeper groundwater wells.Nevertheless, this transition did not resolve the persistent issues of water scarcity and deteriorating water quality.
Nevertheless, the community has demonstrated adaptability to their changing environment.This research identifies a community tactic that holds potential as an alternative approach to addressing WASH (Water, Sanitation, and Hygiene) access challenges, particularly regarding clean water provision.A similar practice was observed in Hamlet Timbulsloko, where rainwater utilization extends beyond plant irrigation, cleaning, and deck floor maintenance.Through interviews with male participants in Hamlet Timbulsloko, it was revealed that rainwater is also used for cooking and drinking.Respondents sought solutions to the high costs associated with obtaining fresh water in Hamlet Timbulsloko.To address this issue, residents in Hamlet Timbulsloko have undertaken a multi-step process involving the collection, observation, and testing of rainwater.
The process begins with the first rain after the dry season, which is allowed to cleanse the roof tiles of the house, acting as a conduit to channel water into storage containers.Additionally, this initial rainwater is utilized for irrigating plants.Subsequent rains during the wet season are collected and stored in buckets.The harvested water is then transferred to water gallons, and its condition is observed for the presence of mold.Thus far, residents in Hamlet Timbulsloko have employed rainwater for various purposes, including household cleaning, plant irrigation, washing, cooking, and even drinking.They have found it advantageous due to its ready availability during the rainy season, cost-effectiveness (as it does not require purchase and eliminates transportation costs associated with buying refill water), and a perceived fresher taste compared to refill water or artesian well water in Hamlet Timbulsloko.
In light of theoretical foundations, the residents of Hamlet Timbulsloko exhibit initiative, demonstrating their capacity to generate innovative solutions to local challenges.This ability stems from daily observations, the utilization of information and data drawn from everyday experiences, and the potential suitability of their findings.Through focus group discussions and live-ins with residents, it became evident that these individuals possess certain characteristics: a curious nature, often inquiring with numerous questions; receptiveness to new knowledge, displaying enthusiasm for acquiring fresh information; resourcefulness, demonstrating creativity in generating ideas beyond the status quo, including the construction of a deck road; and a willingness and ability to conduct observations and research.
Drawing upon the conceptual framework of personal initiative developed by [14], the residents of Hamlet Timbulsloko actively and independently address the clean water scarcity issuein their locality.They do not resign themselves to the prevailing situation.Instead, they engage in self-initiated actions, unassigned by external parties, and proactively undertake tasks such as collecting, observing, and testing rainwater-a targeted response to the water shortage problem.
According to [14], the individual residents' rainwater harvesting initiative in Timbulsloko hamlet can be broadened and expanded to encompass objectives beyond personal goals.This is because the challenges faced by these individuals are shared by the wider community.Furthermore, this indicates that the residents' selfinitiated actions have a significant psychological distance, being undertaken by individuals who, in specific circumstances, can assume the roles and functions of citizens or community members rather than local leaders or policy makers.A visual representation of the civic initiative in Timbulsloko Hamlet aimed at addressing clean water access is presented in Diagram 1.

Conclusion
Rainwater harvesting, as practiced by certain residents along the coastal region of Sayung, holds the potential to evolve into a viable solution for addressing the clean water needs unmet by governmentprovided piped water services administered through PDAM (Perusahaan Daerah Air Minum).Beyond serving as a means to secure clean water for coastal inhabitants, rainwater harvesting represents a valuable effort in water conservation.This aligns with findings by Fayez Abdulla and A. W. Al Shareef in their 2009 study [15], "Roof Rainwater Harvesting System for Household Water Supply in Jordan," where they underscore the significance of rainwater as a crucial water source, particularly in areas devoid of reliable clean water supply systems, grappling with subpar surface water quality, or lacking access to groundwater resources.Abdulla and Shareef emphasize that rainwater harvesting not only serves as an alternative solution for meeting clean water demands but also imparts a vital lesson to communities on the importance of safeguarding water sources.
However, it is worth noting that communal rainwater harvesting, employing sound and appropriate technology, remains an underutilized practice.The rudimentary rainwater harvesting techniques employed by Sayung residents can be elevated to a more refined and targeted approach for providing clean water to coastal communities.This transition presents three distinct opportunities.First, it offers the prospect of meeting the clean water requirements of the community.Second, it provides community members with a platform to translate their local knowledge into practical solutions that are contextually relevant.Third, it presents an opportunity to curtail the over-exploitation of groundwater resources while fostering their preservation.
The third opportunity assumes strategic significance in supporting the government's initiatives, particularly the National Movement for Water Rescue Partnership (GN-KPA) program, aimed at groundwater conservation.Within this program, it is evident that the government shares concerns about the prudent management of Earth's water resources to avert potential scarcity and drought.Consequently, what began as a response to water scarcity through rainwater harvesting should transform into a broader movement.This movement has the potential to amplify awareness about the need for water preservation and protection among a wider populace, ensuring that water scarcity does not become a stark reality in the future.Effectively conserving water necessitates a collective commitment from all stakeholders towards ensuring water sustainability.

Acknowledgment
Researchers would like to thank the Developmen Planning Agency of Central Java Province for financial support in Riset Unggulan Daerah (RUD) Scheme.

Figure 2 .
Figure 2. Former PAMSIMAS Meter Installation in Timbulsloko Hamlet Submerged Under Seawater and Positioned Beneath a Wooden Platform on the Village Road.Source: Primary Survey 2022

Figure 3 .
Figure 3. Former Non-Operational Seawater Desalination Installation in Hamlet Timbulsloko, Some Parts of Which Are Corroded.Source: Primary Survey, 2022Presently, approximately 350 residents of Timbulsloko Hamlet rely on artesian wells (boreholes), locally referred to as "umbul," as their source of clean water.There are two wells with depths of 135 meters and 150 meters currently in use and managed under the Community-Based Water Supply and Sanitation (PAMSIMAS) framework.These two artesian wells were constructed by the Demak District Public Works and Spatial Planning Agency (Dinputaru) in 2014 and 2015, as the seawater desalination plant in Hamlet Timbulsloko ceased functioning.The management of PAMSIMAS with these two wells has encountered similar challenges regarding operational costs.Extracting freshwater from these artesian wells incurs an average monthly cost of Rp 2.2 million and Rp 1.5 million for electricity consumption.Meanwhile, residents are charged a PAMSIMAS tariff of Rp 2,500 per cubic meter.The cumulative payments made by residents for PAMSIMAS water usage cover the electricity expenses and maintenance costs.However, issues have arisen from within the wells themselves, with the volume of freshwater extracted from these two wells gradually diminishing.This has led to the residents of Hamlet Timbulsloko experiencing an insufficient supply of clean water once again.PAMSIMAS administrators suspect a possible underground

Figure 4 .
Figure 4.The Drilling of the Third Artesian Well, Aligned Parallel to the First Well.Source: Primary Survey, 2022

Figure 5 .
Figure 5. Rainwater Collection Using a Bucket to Intercept Roof Runoff.Source: Primary Survey, 2022.

Figure 6 .
Figure 6.Rainwater Storage in Gallons for Watering the Plants and Washing, Following the Precipitation Process in the Roof Runoff Collection Bucket.

Diagram 1 .
Potential Development of Community Initiatives as Citizen Solutions.

Hamlet Timbulsloko Residents) Amplification (Targeting Community Problem Solutions)
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