Strategic Development Plans (SDPs) are prepared by Corporate Joint Committees (CJCs), which are regional groups made up of multiple Local Planning Authorities in each region:
Mae Cynlluniau Datblygu Strategol yn cael eu paratoi gan Gyd-bwyllgorau Corfforaethol, sef grwpiau rhanbarthol sy'n cynnwys nifer o Awdurdodau Cynllunio Lleol ym mhob rhanbarth: