In terms of funding, students will need to apply for this independently. Once you are accepted into the program, and once you are registered at McGill, you can apply for Research Assistant (paying between 4000-10000$) and Teaching Assistant (~1500$ each) positions. For TA positions, you will need to consult the department website in the fall and winter terms. For RA opportunities, you will need to email professors who match your research interests to see if they have any RA positions available. There are also around 4-5 scholarships within the IWRM Program available for the internship projects (between 7000 - 10000$) that you can apply for. Many of the internships available to MSc in IWRM students are paid. Examples include 2-4 full scholarships every summer at Technion University, Herbrew University, BenGurion University, and the UK.
More information on scholarships, fellowships, bursaries and awards can be found on the following websites: