Riyadh Municipality has participated in "Our City is Our Responsibility" Conference held in Salalah, in Sultanate of Oman, on 12-13 September 2018), organized by Dhofar Municipality, Arab Institute of Planning, and Al Reaiya Al Oula Company for organizing conferences and seminars, in attendance of delegation of specialists in Riyadh Municipality namely, Eng. Khalaf bin Za’ar Al-Dalbhi, Director General of Studies and Designs, Eng. Yahya bin Mousa Atiq, Head of Arqa Sub-municipality, and Eng. Falah bin Ali Al-Qahtani, Head of Al-Ha'ir Sub-Municipality.
Eng. Khalaf Al-Delbhi reviewed the experiences of developing and rehabilitating valleys in Riyadh by presenting a paper entitled "Wadi Hanifa and Wadi Al-Sulai - the Sustainable Valleys of Riyadh", which included efforts of Riyadh Development Authority to rehabilitate and develop Wadi Hanifa, and development stages from cleaning and removal of waste, and rehabilitation of the valley stream, and the implementation of all services and public facilities of roads and walkways, lighting, landscaping and parks, as well as establishment of a permanent water channel, and the system of water vital treatment in valley stream, in addition the project included al Ha’ier lakes and nature reserves وuntil the valley has become a destination for residents of the capital for hiking and entertainment, pointing to obtaining international awards for this important project.