Integrated water management is a wicked public policy problem with no clear path to resolution. This dissertation is an in-depth qualitative comparative analysis of two collaborative governance processes created to tackle complex water problems in New Zealand and Oregon, U.S.A. Both cases convened a wide range of state and non-state actors in efforts to find common ground, build consensus for change, and develop innovative water policy solutions. The goal of this comparative case study analysis is to gain a better understanding of collaborative network governance frameworks as applied to integrated water management and primary factors for success. The proposition posits that collaborative networks involving public, private, and non-profit actors are better equipped than government-driven efforts to develop desired outcomes. To test this proposition, the research questions probe the role of state and non-state policy actors, conditions for collaboration, strength of actor ties, development of trust and social capital, barriers to success, and the role of climate change as a policy driver in these two case studies. The comparative case study analysis yields fascinating insights that adds to the network governance literature. In the New Zealand case, a collaborative-led process called the Land and Water Forum (LAWF) showed that this ongoing network offers benefits to creating consensus on complex water issues. LAWF succeeded in moving policy conversations forward where previous government-led efforts had failed. Within the LAWF collaborative network, non-state actors formed strong ties; however, relationships with state actors exhibited weaker ties. With Oregon's integrated water policy, a collaborative network approach created a more conducive environment for meaningful dialogue among vested interests, and built some levels of interdependency and trust, thus generating a wider array of policy options than through previous legislative and bureaucratic efforts. However, long-standing political, legal, and institutional challenges continue to constrain effective integrated water management and the delivery of integrated outcomes in Oregon. The Oregon case did not exhibit strong leadership within the collaborative to broker challenging policy issues. Also, it faced implementation challenges as one state agency was given responsibility for stewarding integrated water management but lacked authority for implementation or coordination with other state agencies. Overcoming fragmented natural resource governance arrangements remains a daunting challenge. This research revealed three key findings: (1) in both cases, collaborative network governance worked well for framing and designing new integrated water policies, but encountered implementation challenges; (2) managing the complexities around the intersection of top-down, vertical command and control governance with horizontal collaborative approaches remains an ongoing challenge to New Public Governance; and (3) the two cases represent examples of the use of formal and informal processes for policy development. The benefits of collaborative governance for policy development are substantial, and the limitations appear to be obstacles to overcome and not fatal flaws. The main challenge lies in transitioning from policy and planning to implementing changes on the ground affecting the way we manage water today and in the future.