Under the new water control philosophy, reclaimed water utilization is an important strategic measure to increase water supply and reduce water environmental pollution. This has important implications for addressing the water crisis in urban development. The scientific and reasonable price of reclaimed water has a positive effect on promoting the utilization of reclaimed water and improving the utilization rate of urban reclaimed water. Therefore, this study extracted the influencing factors of reclaimed water price through grounded theory and used the ISM method to elucidate the logical hierarchy and investigate their influencing mechanisms. The results indicate that the structural system of factors affecting the price of reclaimed water was composed of 16 factors, which could be divided into four hierarchical levels. Among them, the external value of reclaimed water utilization, the technical level of reclaimed water processes, the regional economic development level, and the quality differences between reclaimed water and conventional water were the deep-rooted factors that affect the price of reclaimed water. In the end, the policy implications regarding the management of reclaimed water prices were proposed from the perspectives of surface-level direct factors, middle-level indirect factors, and deep-rooted factors.

Digitalization is reshaping environmental governance by enabling real-time data collection, information sharing, and coordinated regulatory action. However, how heterogeneous enterprise digitalization modes, compliance-oriented digitalization, and deep digitalization affect multi-actor digital collaborative governance for carbon mitigation and pollution reduction remain underexplored. This study develops a tripartite evolutionary game model involving the government, enterprises, and the public. The model distinguishes enterprises’ digitalization modes and examines how government digital regulation, enterprise carbon mitigation and pollution reduction strategies, and public participation co-evolve under different cost–benefit conditions. Through numerical simulations and theoretical analysis, the study identifies critical factors of stakeholders’ strategies and proposes possible evolution paths for digital collaborative governance. The results show that (1) the system can evolve toward an ideal stable equilibrium: government digital regulation, enterprise carbon mitigation and pollution reduction, and active public participation; there is a high probability that enterprises will adopt a deep level of digitalization. (2) Subsidies for deep digitalization can increase the probability of enterprise deep digitalization, but excessive subsidies may increase fiscal pressure and destabilize government digital regulation. Compared with subsidy intensity, the additional benefits of digital collaborative governance accruing to enterprises are more important in promoting the transition from compliance-oriented to deep digitalization. (3) Public participation and government digital regulation both contribute to the stability of digital collaborative governance. Higher public participation significantly accelerates system convergence, while government digital regulation remains sustainable when digital collaborative governance benefits can offset construction and operating costs. These findings clarify the conditional logic of digital collaborative governance and offer actionable policy implications.

Unconventional water includes reclaimed water, harvested rainwater, desalinated seawater, and mine water. Unconventional water use is considered more of a “mandatory responsibility” in China. The initial allocation of unconventional water emphasizes quantity-centered responsibility allocation while the minimum utilization reflects this responsibility. The unconventional water use responsibility (UWUR) should be tailored to the characteristics of each area, moving away from a ‘more is better’ mindset. However, there is a large research gap in this field. This paper first presented six fundamental principles for unconventional water allocation. Ensuring fairness in allocation involves aligning the allocated amount with urban water usage characteristics. Hence, based on four key features, this paper integrated various socioeconomic and environmental factors to build an initial allocation model. To enhance efficiency, an optimal allocation model was constructed using the zero-sum gains–data envelopment analysis (ZSG-DEA) method. The models were then applied to Jiangsu Province, China, to verify their applicability. The results showed that the projected minimum UWUR allocation (unit: 100 million m³) for each city in 2025 is 1.482 (Nanjing), 1.501 (Wuxi), 0.919 (Xuzhou), 1.029 (Changzhou), 2.977 (Suzhou), 1.497 (Nantong), 0.818 (Lianyungang), 0.766 (Huai’an), 0.875 (Yancheng), 0.920 (Yangzhou), 0.790 (Zhenjiang), 0.858 (Taizhou), and 0.766 (Suqian). The rational and feasible results indicated that the allocation framework proposed in this paper has a certain practicability. Lastly, this paper considered the differences in unconventional water utilization conditions across 13 cities and proposed corresponding measures to improve the utilization. This paper represents a tentative exploration of unconventional water allocation in China and offers theoretical and practical insights for policy-makers to improve territorial spatial planning and sustainable water management.