Sustainable Water Management

Integrated water resources management (IWRM) is a key concept of water management in the twentieth century. The definition developed by the Global Water Partnership in 2000 is too penetrating the academic and decision-maker society. Although the concept of IWRM has a long history of more than 70 years, many critiques of the currently accepted definition have been generated by water scientists. Reconsideration of IWRM from the viewpoint of design science and especially sustainability science is important for creating new perspectives of IWRM. The use of IWRM toward a sustainable society was examined in relation to water sustainability and the evaluation of a water resources development project with sustainability. During the 7th World Water Forum (WWF7) in Korea in 2014, the Organization for Economic Co-operation and Development (OECD) proposed “Principles on Water Governance: From Vision to Action,” and the World Water Council (WWC) reported a discussion paper entitled “Integrated Water Resource Management: A New Way Forward.” Through the review of these international trends, the largest impact factor affecting IWRM is climate change. The influence of climate change on water issues became clear by the International Panel on Climate Change Fourth Assessment Report (IPCC AR4), and a strategic adaptation plan and methods for IWRM were proposed.

Participatory approaches that feature the broad inclusion of local stakeholders have become a basic design requirement for future water resources management. However, the actual implementation of an effective management plan currently remains a challenge. In this chapter the authors focus on the concept of “system integration” in integrated water resources management (IWRM) as the root cause of the problem. More than ten years have passed since the publication of Asit K. Biswas’ ultimately critical treatise, wherein he argued that although he could understand the necessity for IWRM, it cannot be reflected in management plans. Nonetheless, this problem continues to be neglected. We argue in this chapter that the problem exists in ways of thinking that are predicated on hard-path water resources management. In the conclusion, we discuss the outlook for the alternative soft-path, adaptive management, using an aborted dam project in Japan as a regional case study.

Environmental assessment is key in designing a local framework for integrated water resources management dealing with land-use and climate change. We involved local residents in acquiring environmental data to clarify significant land-use and climate changes in watershed and field scales. In the watershed scale, a series of daily climate data was collected from three automatic weather stations, each available in the upstream, midstream, and downstream areas of the Saba Watershed from 2007 to 2014. The annual rainfall pattern changed; it decreased in all the stations after 2010. The annual rainfall downstream was always lower than at the other two stations located at higher elevations. As a consequence, the downstream area had the earliest and the longest dry season compared to the other areas. In the field scale, climate conditions were assessed on the basis of intensive measurements using automatic weather stations and soil sensors in three representative locations. Based on the monitored data in the context of climate change, the optimal planting date during a year was October 15 (first season), February 13 (second season), and June 12 (third season). We estimated that the irrigation water requirement was 108, 283, and 751 mm, respectively. We recommend constructing a rainwater reservoir to store more irrigation water.

To assess the effects of differences in land use in a mountainous sub-watershed on water conservation, namely, hydrological services like flood control and groundwater recharge, first, this chapter aims to present a water balance analysis in two sub-watersheds located upstream of the Saba River watershed. Specifically, the Titab and the Busungbiu-Tunju were compared. An annual water balance analysis in the two sub-watersheds in 2013 and 2014 revealed that the ratio of base flow to the total discharge was larger in the Titab, which has a lower areal percentage of clove plantation, a higher percentage of coffee plantation, and a slightly higher percentage of natural forest than the Busungbiu-Tunju. Second, by applying the International Center for Water Hazard and Risk Management/Public Works Research Institute (ICHARM/PWRI) distributed hydrological model, discharges under the present land use and three scenarios of changed land use were predicted. By converting all coffee plantations to clove plantations, base flow decreased, direct runoff increased, and the peak discharge increased. By converting clove plantations at high elevation to coffee plantations, base flow increased, direct runoff decreased, and the peak discharge decreased when compared with the present. In converting all land uses to natural forests, base flow was the largest, direct runoff was the smallest, and the peak discharge was the smallest of all cases. Comparison between the three land uses, coffee plantations, clove plantations, and natural forests, revealed that the clove plantation has the highest possibility of causing a flood disaster, the coffee plantation has a possibility of preventing a flood disaster and increasing groundwater, and the natural forest has the highest possibility of preventing a flood disaster and increasing groundwater.

Integrated water resources management (IWRM) for the Saba River Basin began as a pilot project undertaken by the Research Institute for Humanity and Nature (RIHN), Japan and Bogor Agricultural University (IPB), Indonesia (2012–2016). A participatory approach through multistages of multistakeholders’ meetings has enhanced participation in implementing the IWRM concept. The research project has successfully improved the multistakeholders’ capacity with regard to IWRM; their participation in strength, weakness, opportunity, and threat (SWOT); and identification of key development issues within the Saba River Basin. They have also improved the decision-making processes through every stage as identified by the accomplishment of some important common agreements, such as the need for a forum for IWRM entitled the Saba River Basin Community (the “Community”), as well as its vision, role, function, organization structure, basic rules, priority programs from 2015 to 2020, and action plans in 2015/2016. However, the Committee must now transition into a concrete activity and push for action through a process of trial and error that will build the future. Obviously, the Community will be more effective in fulfilling its roles if it has appropriate financial and legal support.

On-site water sampling surveys were carried out from 2012 to 2014 to sample rainwater, river water, and paddy water in the Saba River Basin in Bali Island and three caldera lakes adjacent to this basin, in order to characterize the different isotopic ratios in this range of water samples. The results showed that the water isotopic ratios of river water could be expressed by the linear combination of the isotopic ratios of the constituent waters such as rainwater and paddy water. Furthermore, the results suggested that there was likely a stable inflow from the caldera lakes, which were located outside of the basin area, to the Saba River via its tributaries (the Panas River and the Ling River). Based on the water isotopic relationship, the return flow from the paddy fields was inferred to contribute considerably to the river flow to the extent beyond its area ratio to the total basin area, especially in dry seasons. We concluded that the caldera lakes and the paddy irrigation practices in the Saba River Basin contributed to the stabilization of the river water flow and that this contribution was especially strong in the dry seasons. The water isotopic properties should be regarded as “scientific information for society,” which can provide strong support for the diagnosis of river basins and decision-making for water resources management in the future.

The authors consider the meaning of dam construction in the context of water resources management, based on the Titab Dam construction case study in Indonesia. The Titab Dam was built to supply irrigation water for 1794.82 ha of downstream irrigated paddy fields, provide domestic water for 72,263 potential household connections, reserve 1.5 MW of electricity, conserve water resources within the Saba River Basin, and develop fishery agro-eco-tourism activities. Besides the economic and environmental benefits, the construction of the Titab Dam also brought adverse impacts, including the disappearance of Subak Dukuh after the Subak Temple was destroyed; inundating of all paddy fields in Subak Dukuh (13 ha); flooding almost all of the paddy fields in Subak Asah Uma (18 ha); and destroying farmers’ livelihood inside both Subak Dukuh and Subak Asah Uma. To achieve optimal multi-functionality and effectiveness of the Titab Dam, the top two priorities are implementation of garbage control and soil and water conservation action plans, as carried out by the Saba River Basin Community.

Chongming Island is the largest alluvial island in the world and is an ecologically sensitive area. It has 15,924 rivers with an overall length of 9352.3 km. Rapid economic growth in Chongming has presented great challenges to its water resource managers because of a scarcity of water resources, severe water pollution, growing domestic and industrial water demands, and the requirement for food security. This paper provides an overview of water resources and their management in Chongming. It describes the key water issues faced in Chongming, as well as the institutional, legal water regulatory arrangements, and the construction of an eco-island to address these challenges, including approaches to water resource allocation and management, pollution control, and water supply regulations. This paper concludes with a discussion of the priorities and challenges for water management, the progress that has been made, and the improvements that will be required to ensure the long-term sustainability of water resources in Chongming Island.

In order to study the trophic status of rivers in Chongming Island, the temporal and spatial variations of environmental factors and their interaction mechanisms in the main rivers were investigated. Results showed that eutrophication was present in the main rivers of Chongming Island. The concentrations of nitrogen and phosphorus in the main rivers were high, and nitrogen pollution was particularly severe. In fact, those nutrients mainly originated from the Yangtze River, rather than the local source in this island. Except for in winter, the chlorophyll-a content in most of the main rivers reached some level of eutrophication. The appearance of phosphorus promoted the growth of algae; this was due to water from the Yangtze River entering the main rivers. The evolution of the algae population accorded with the PEG model, as follows: winter (diatom), spring (chlorophyta and diatom), summer (cyanobacteria and chlorophyta), and fall (diatom). In addition, the trophic state index (TSI_M) indicated that rivers were at the “heavy eutrophication” level in spring and summer, and the “eutrophication” level in winter and autumn. In summer, chlorophyll-a and TP were the main contributors to the trophic status of the rivers.

As the world’s largest alluvial island and China’s third largest island, Chongming enjoys significant geographical and ecological resources, which enables it to be at the forefront of Shanghai’s future sustainable development. Ecological construction and environmental conservation are the two key development principles for the island’s planning. With the support of a series of favored development strategies and policies, the process of urbanization in Chongming has been accelerating since the 2000s. This has triggered further changes in land use/cover and the local water environment. However, questions relating to (1) the extent to which the local environment has been affected by urbanization and (2) the policy implications of managing urbanization to achieve sustainable development have not yet been explicitly answered. Therefore, this chapter focuses on an assessment of the impact of urbanization on land use/cover change and the water environment by integrating statistics and remote sensing data. More importantly, certain policy deliberations related to ecological planning, water management, and the development of a low-carbon society are proposed to support the decision-maker in putting the eco-island plans into practice.

Recently, the development of a stable water supply that responds to increasing water demand has been difficult because the spatial-temporal unfair distribution of water resources in the world has expanded due to climate change. Therefore, in regions with a water shortage, it is becoming more and more important to reclaim and reuse water. In this chapter, we first introduce our interdisciplinary research project that has been focused on water reclamation/reuse. The project consisted of four groups: “Reclamation and Recycle Group,” “Material Recycle Group,” “Green Space Creation Group,” and “Management and Policy Group.” Then, we introduce the concept of greywater for water reclamation/reuse and show the characteristics of greywater quality in general households of semi-urban regions in Thailand, experimental results from laboratory scale experiments, and acceptance of treated greywater from residents in three Asian countries. Additionally, we show the current situation of rainwater and reclaimed water uses in university campuses and propose a new strategy regarding eco-houses of the future.

Ensuring sufficient unpolluted water for urban, agricultural, and industrial use is arguably the most important issue facing the world’s communities. Countries such as Australia are currently unable to supply enough water to many areas in times of drought, and it is estimated that perhaps a billion people in the Asia-Pacific Region face the prospect of unsafe water at all times. This chapter and book take a new and skeptical look at some of the underlying factors that affect the management of this vital resource and the proposed solutions. Traditionally, water management policies and practices have dealt only with problems of water distribution to meet the ever-increasing demand, rather than better management of existing resources. The largely fragmented approach that results has contributed to the overexploitation of water resources. Nevertheless, in many parts of Australia, China, South Africa, Canada, the United States, Europe, Japan, and elsewhere, efforts are currently being made to better manage water distribution systems using proactive methods instead of simply reacting to supply and demand problems. Proactive management methods include new ways of accounting for water and methods for reducing losses, as well as benchmarking against international high performers. However, there are no across-the-board solutions since context matters and managers must therefore learn from local operating experience. The difficulties experienced by integrative efforts in this situation indicate that a significant part of the problem lies in the structures of governance in the water industry. Water management should be a regional, national, and international level concern, and it is in many places but generally at the level of policy rather than responsibility for infrastructure and pricing of water.