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This case study uses the concept of ecosystem services and specifically payments for ecosystem services, alongside five experiences from the Westcountry Rivers Trust (WRT), which celebrates its 30th anniversary in 2024, to demonstrate the need for integrated catchment management (ICM). It highlights the multifaceted benefits that ecosystems provide to human well-being, the challenges faced in managing these often-siloed services and the role of ICM in preserving and enhancing multiple ecosystem services, focusing on the water-related drivers of flooding, drought, water quality and aquatic biodiversity. Through WRT projects this case study highlights practical applications and successes in managing ecosystem services at the catchment level and what considerations are needed for future integration and delivery of multi-benefit solutions. This paper is derived in part from the interviews and workshops undertaken as part of the Atlantic Area Interreg funded Triple C project (EAPA_772/2018), as well as contributions from the Horizon funded, InnWater project (Horizon EUROPE No. 101036683 and UKRI No. 10066637) and the OFWAT-funded, mainstreaming Nature-based Solutions.

Abstract Catchment floods are more challenging due to intensive urbanization and climate change. Enlightened by the Low Impact Development (LID), China initiated the Sponge City Program (SCP) to transform Urban Flood Management (UFM) to be more environmentally friendly in 2013. The China National Government (CNG) has subsidized municipal SCP facilities to enhance urban flood resilience while delivering multiple co‐benefits for urban ecosystems and social well‐being. Recent floods at Schleiden (Germany), Arizona State (USA), and Zhengzhou (China) in 2021 reflected the necessity of Catchment Flood Management (CFM) to cover the whole catchment scale. The SCP, designed to handle small‐scale urban pluvial floods, has brought concerns when facing larger‐scale fluvial floods after the Zhengzhou 2021 flood. Indeed, catchment‐scale Natural Flood Management (NFM) can manage fluvial floods while improving flood adaptations sustainably from upstream to downstream reaches. This research develops a new framework named the Sponge Catchment Management Plan (SCMP), including structural and Nonstructural elements. On the structural side, the SCMP framework integrates NFM with the SCP and Grey Engineering (GE) for reducing the fluvial flood discharge peaks in the whole‐catchment scale. On the nonstructural side, the SCMP encourages collaborative governance, revising technical standards, and improving “bottom‐up” participation. This research used Semi‐Structured Interviews (SSIs) and a Focus Group Approach (FGA) to explore 62 professional and Nonprofessional stakeholders’ perspectives on the SCMP framework. Some professional respondents did not know much about the NFM and were worried about the effectiveness of this practice. But most interviewees supported the SCMP pilot work and shared the co‐benefits from the NFM. This case study at the SW China, Guiyang, could be a lesson to encourage other Chinese cities further implement SCP to improve catchment‐scale flood resilience.

In the UK, most large reservoirs constructed for public water supply are in upland areas. Many are situated in catchments characterised by organic-rich soils, including peatlands. Although these soils naturally leach large amounts of dissolved organic matter (DOM) to water, the widespread degradation of upland peat in the UK is believed to have exacerbated rates of DOM loss. High and rising DOM concentrations in these regions raise treatment challenges for the water industry. In the UK, water companies are increasingly considering whether upland-catchment peat restoration measures can slow down or even reverse rising source water DOM concentrations and, thus, reduce the need for more costly and complex engineering solutions. There remains considerable uncertainty around the effectiveness of such measures, and a comprehensive overview of the research in this area remains lacking. Here, we review the peer-reviewed evidence of the effectiveness of four catchment management options in controlling DOM release from peat soils: ditch blocking, revegetation, reducing forest cover and cessation of managed burning. Results of plot-scale investigations into the effects of ditch blocking on DOM leaching are currently largely equivocal, while there is a paucity of information regarding impacts at spatial scales of more direct relevance to water managers. There is some, although limited, evidence that the terrestrial vegetation type may influence DOM concentrations and treatability. The presence of plantation forestry on peat soils is generally associated with elevated DOM concentrations, although reducing forest cover appears to have little short-term benefit, and associated disturbance may even increase concentrations further. Catchment management measures have rarely been monitored with downstream water quality as the focus. To mitigate the uncertainty surrounding restoration effects on DOM, measures should be undertaken on a site-specific basis, where the scale, effect size and duration of the intervention are considered in relation to subsequent biogeochemical processing that occurs in the reservoir, the treatment capacity of the water treatment works and future projected DOM trends.

Agricultural water is not equitably shared in South Africa. A substantial proportion of water is in the hands of large commercial farmers and the water access of smallholder farmers is limited. Policies and strategies developed since 1994 to ensure equal access to productive water have had little impact. This paper presents an analysis of the challenges of accessing water through the water user licence process in the Breede-Gouritz Catchment Management Agency (BGCMA) of South Africa. A review of the national Water Allocation Reform (WAR) programme and the related BGCMA strategies was carried out. Interviews were conducted with smallholder farmers and with key officials responsible for water allocation processes in the BGCMA and other water-related institutions; the Framework of Water Governance by Franks and Cleaver (2007) was used to analyse the processes. Results revealed that existing lawful water use continues to privilege previously advantaged commercial farmers and that smallholder farmers’ access to productive water is hampered by lack of human and financial capacity within the institutions that support them, and by limited coordination among these institutions. A water allocation unit at the BGCMA that specifically deals with water licencing is necessary to speed up the process and to enable local people to inclusively participate in water resource management.

Use the ICM model as a tool to investigate, analyze and summarize the basic data of the sewage system to form a sewage system database to construct the sewage pipe network model topology. Use the model checking tool to check and carry out the error data in the pipe network during the model building process. The second re-survey makes the topology of the model more accurate. Determine the relevant parameters of the model through on-site investigations, query relevant information and relevant literature, use the basic data provided by relevant departments to set the flow process line and delimit the population of the catchment area, and use the measured daily cumulative flow data of the pumping station and the sewage treatment plant. The average value of the influent water quality index is used to calibrate and check the model, and build a credible hydraulic model and water quality model of the sew-age pipe network. The checked sewage pipe network model is used to evaluate the current status of the sewage system. The current water delivery capacity of the pipe network is analyzed from the three perspectives of pipeline overload status, flow rate, and pump station operating status. The pipeline is at fa load or even Overload operation, the current operating state is poor. A simulation comparison of different sediment depths shows that the clogging seriously affects the water delivery capacity and regulation and storage capacity of the pipeline network. [ABSTRACT FROM AUTHOR]

Under the dual pressures of climate change and urbanization, cities in China are experiencing increasingly severe flooding. Using the Yushan Lake area in Ma'anshan City, Anhui Province, as a case study, we employed the InfoWorks Integrated Catchment Management (ICM) hydraulic model to analyze the drainage and flood prevention system of the region and assess the current infrastructure for drainage and flood control. There are 117 pipelines with a return period lower than one year for stormwater and combined sewer systems, accounting for 12.3% of the total number of pipelines. The number of pipelines meeting the one-year but not the three-year return period standard is 700, representing 70.2%. Only 17.5% of the pipelines are capable of handling events exceeding the one-year standard. In simulating a 24 h, 30-year return period rainfall event, the results indicate that floodwater accumulation in the study area is predominantly between 0.15 m and 0.3 m. Most risk areas are classified as low risk, covering an area of 36.398 hectares, followed by medium and high-risk areas, which cover 8.226 hectares and 3.087 hectares, respectively. The Ma'anshan Yushan Lake area has, overall, certain flood control capabilities but faces flood risks during storms with return periods exceeding three years. This research offers valuable insights for improving urban flood management in Ma'anshan City through the development of a stormwater management model for the Yushan Lake area. [ABSTRACT FROM AUTHOR]

Agricultural water is not equitably shared in South Africa. A substantial proportion of water is in the hands of large commercial farmers and the water access of smallholder farmers is limited. Policies and strategies developed since 1994 to ensure equal access to productive water have had little impact. This paper presents an analysis of the challenges of accessing water through the water user licence process in the Breede-Gouritz Catchment Management Agency (BGCMA) of South Africa. A review of the national Water Allocation Reform (WAR) programme and the related BGCMA strategies was carried out. Interviews were conducted with smallholder farmers and with key officials responsible for water allocation processes in the BGCMA and other water-related institutions; the Framework of Water Governance by Franks and Cleaver (2007) was used to analyse the processes. Results revealed that existing lawful water use continues to privilege previously advantaged commercial farmers and that smallholder farmers' access to productive water is hampered by lack of human and financial capacity within the institutions that support them, and by limited coordination among these institutions. A water allocation unit at the BGCMA that specifically deals with water licencing is necessary to speed up the process and to enable local people to inclusively participate in water resource management. [ABSTRACT FROM AUTHOR]