Sustainability Assessment Model of the Buriganga River Restoration Project in Bangladesh: A System Dynamics and Inclusive Wealth Study

The Bangladesh government initiated the Buriganga River Restoration Project in 2010 to clean the heavily polluted Turag-Buriganga River. This study assessed the dynamic impact of the project on intergenerational well-being and developing a sustainable river system. The project outcomes were modeled for three future scenarios—varying waste control, streamflow, and migration control levels. System dynamics modeling—based on Streeter-Phelps’ water quality model and inclusive wealth (IW) index—was applied to secondary data (including remotely sensed data). The simulation model indicated that the project (with increasing streamflow up to 160 m3/s) will not ensure sustainability because dissolved oxygen (DO) is meaningfully decreasing, biological oxygen demand (BOD) is increasing, and IW is declining over time. However, sustainability can be achieved in scenario 3, an integrated strategy (streamflow: 160 m3/s, waste control: 87.78% and migration control: 6%) that will ensure DO of 8.3 mg/L, BOD of 3.1 mg/L, and IW of 57.5 billion USD in 2041, which is equivalent to 2.22% cumulative gross domestic product by 2041. This study is the first to use combined modeling to assess the dynamic impacts of a river restoration project. The findings can help policymakers to achieve sustainability and determine the optimal strategy for restoring polluted rivers.

Resilient Organizations for River Restoration: The Case of Two Colorado River Sub-Basin Recovery Programs

This study characterizes the resilience of organizations undertaking river basin governance and recovery. The Upper Colorado River Endangered Fish Recovery Program (UCREFRP) and the Lower Colorado River Multi-Species Conservation Program (LCR-MSCP) are defined in this study as polycentric organizations nested within larger institutional mechanisms governing the Colorado River Basin. This study utilizes an environmental disturbance-organizational response framework to characterize organizational resilience—and uses attitudinal diversity (characterized by attitudes toward agendas) as the measurable metric. Environmental disturbances are defined as either press or pulse and categorized as either institutional or biophysical in nature. Four types of attitudinal diversity metrics are utilized—supportive, clarifying, conditional, and critical. Results indicate that institutional press and pulse events generated anticipatory resilience capabilities along with some adaptive capabilities for the organizations. However, the biophysical press and pulse events only reveal coping capabilities and very little adaptive capabilities. With the recent Colorado River shortage declaration, it is critical for the programs to build anticipatory as well as adaptive capabilities for optimal response to biophysical press events.

Best Practices for Monitoring and Assessing the Ecological Response to River Restoration

Nature-based solutions are widely advocated for freshwater ecosystem conservation and restoration. As increasing amounts of river restoration are undertaken, the need to understand the ecological response to different measures and where measures are best applied becomes more pressing. It is essential that appraisal methods follow a sound scientific approach. Here, experienced restoration appraisal experts review current best practice and academic knowledge to make recommendations and provide guidance that will enable practitioners to gather and analyse meaningful data, using scientific rigor to appraise restoration success. What should be monitored depends on the river type and the type and scale of intervention. By understanding how habitats are likely to change we can anticipate what species, life stages, and communities are likely to be affected. Monitoring should therefore be integrated and include both environmental/habitat and biota assessments. A robust scientific approach to monitoring and appraisal is resource intensive. We recommend that appraisal efforts be directed to where they will provide the greatest evidence, including ‘flagship’ restoration schemes for detailed long-term monitoring. Such an approach will provide the evidence needed to understand which restoration measures work where and ensure that they can be applied with confidence elsewhere.

Defining Recovery Potential in River Restoration: A Biological Data-Driven Approach

Scientists and practitioners working on river restoration have made progress on understanding the recovery potential of rivers from geomorphological and engineering perspectives. We now need to build on this work to gain a better understanding of the biological processes involved in river restoration. Environmental policy agendas are focusing on nature recovery, reigniting debates about the use of “natural” reference conditions as benchmarks for ecosystem restoration. We argue that the search for natural or semi-natural analogues to guide restoration planning is inappropriate due to the absence of contemporary reference conditions. With a catchment-scale case study on the invertebrate communities of the Warwickshire Avon, a fifth-order river system in England, we demonstrate an alternative to the reference condition approach. Under our model, recovery potential is quantified based on the gap between observed biodiversity at a site and the biodiversity predicted to occur in that location under alternative management scenarios. We predict that commonly applied restoration measures such as reduced nutrient inputs and the removal of channel resectioning could be detrimental to invertebrate diversity, if applied indiscriminately and without other complementary measures. Instead, our results suggest considerable potential for increases in biodiversity when restoration measures are combined in a way that maximises biodiversity within each water body.