The Toolbox by the Global Water Partnership offers a lot of information on institutional roles in the water sector. It offers two main informational sectors in this topic, one sector for creating an organisational framework and one for building institutional capacity.
GWP (2003): B1. Creating an organisational framework. In: Sharing knowledge for equitable, efficient and sustainable water resources management. Global Water Partnership (GWP), pp.35-57 URL [Accessed: 15.04.2019]