Distributed volunteer computing enables scientists to constitute platforms that can be used for computation tasks by utilizing millions of computers connected to the internet. Volunteer computing is a widely-used approach for many scientific projects including analysis of radio signals for signs of extraterrestrial intelligence and determining the mechanisms of protein folding. User adoption and dependence on desktop software for clients is a challenge in volunteer computing projects. This project presents a generic web-based volunteer computing framework that requires only a web browser to participate in distributed computing projects. A relational database system is implemented on the framework to schedule tasks to volunteers and distribute all the data and modeling code that will run on volunteer computing instances on the client-side. The framework provides distribution and scaling capabilities for projects that have user-base with thousands of volunteers. The framework is tested and evaluated with an operational state-wide hydrological flood forecasting model.