For residential developments to proceed to occupancy, clean treated water and sanitary sewage conveyance and treatment is required. Both services are dependent on Region of York systems and servicing allocation. Since 1996 the construction and delivery of these services have not kept pace with the market demand for residential development, and has required allocation and monitoring of servicing capacity. The Region has restricted the amount of residential development based on the available services being in place by providing servicing allocation to each municipality which are connected to the southern water system and the York Durham Sewage System (YDSS). This servicing allocation is provided by population assignments by the Region to local municipalities and converted to unit type by using a person per unit multiplier for singles, semi-detached, townhouse and apartment units.