Watershed plans
 24. (1) Every upper-tier municipality and single-tier municipality shall have a watershed plan that meets the requirements of subsection (3) for every watershed whose streams originate within the municipality’s area of jurisdiction. O. Reg. 141/17, s. 16 (1). (2) The objectives and requirements of each watershed plan shall be incorporated into the municipality’s official plan.  O. Reg. 140/02, s. 24 (2). (3) A watershed plan shall include, as a minimum, (a)  a water budget and a water conservation plan as set out in section 25; (b)  land and water use and management strategies; (c)  a framework for implementation, which may include more detailed implementation plans for smaller geographic areas, such as subwatershed plans, or for specific subject matter, such as environmental management plans; (d)  an environmental monitoring plan based on a minimum of five years of monitoring; (e)  provisions requiring the use of environmental management practices and programs, such as programs to prevent pollution, reduce the use of pesticides and manage the use of road salt; (f)  criteria for evaluating the protection of water quality and quantity, hydrological features and functions, including criteria for evaluating the impacts of proposed development and infrastructure projects within and outside the Plan Area on water quality and quantity and on hydrological features and functions; (g)  an evaluation of the assimilative capacity of the watershed to deal with sewage from surrounding areas; and (h)  an assessment of climate change impacts on sewage and water service systems and stormwater management systems. O. Reg. 140/02, s. 24 (3); O. Reg. 141/17, s. 16 (2-5). (4) Major development is prohibited unless, (a)  the watershed plan for the relevant watershed, prepared in accordance with subsection (3), has been completed; (b)  the major development conforms with the watershed plan; and (c)  a water budget and a water conservation plan, prepared in accordance with section 25 and demonstrating that the water supply required for the major development is sustainable and that assimilative capacity with respect to sewage is sufficient, has been completed. O. Reg. 140/02, s. 24 (4); O. Reg. 141/17, s. 16 (6). (5) Subsection (4) applies to every application commenced on or after April 23, 2007.  O. Reg. 140/02, s. 24 (5). (6) Subsection (8) applies to every application commenced before the date mentioned in subsection (5), except an application described in subsection (7).  O. Reg. 140/02, s. 24 (6). (7) Clause (4) (c) applies to every application that is commenced on or after April 22, 2004 and relates to the part of The Regional Municipality of York that is served by the Yonge Street Aquifer.  O. Reg. 140/02, s. 24 (7). (8) An application for major development to which this subsection applies shall not be approved unless, (a)  the relevant municipality has complied with clause (4) (c); or (b)  the applicant, (i)  identifies any key hydrologic features and related hydrological functions on the site and how they will be protected, (ii)  demonstrates that an adequate water supply is available for the development, and that there is sufficient assimilative capacity to deal with the sewage from the development, without compromising the ecological integrity of the Plan Area, and (iii)  provides, with respect to the site and such other land as the approval authority considers necessary, a water budget and a water conservation plan that, (A)  characterizes groundwater and surface water flow systems by means of modelling, (B)  identifies the availability, quantity and quality of water sources, and (C)  identifies water conservation measures.  O. Reg. 140/02, s. 24 (8); O. Reg. 141/17, s. 16 (7-9).