Yes Ganaane is the Somali name for Tana. It's in many old local poems in Garissa. Whenever Somalis decide to incorporate Oromos, they always file them under Dir. Wardey are and were Oromo. Most were killed or fled after the Conquest to become the Orma in Tana River county in Kenya today. Those that remained became slaves owned by Absame Harti and Mareexaan. After many wardey slaves killed their owners, a grand council amongst the conquerers was held in the late 1800s in either Wajeer or Afmadow I can't remember. They discussed how to stop the slaves killing their masters (they weren't treated that well). A list of conditions were agreed to placate the slaves and improve their condition. The Harti and Absame agreed but Mareexaan refused. Mareexaan reasoned that as long as a master slave relationship existed, the killings would continue. Mareexaan held a grand council and then decided that each slave would claim the subclan of his master and the Mareexaan Wardey became simply Wardey overnight (just stating facts don't hate me). The Ogaadeen wardey were mostly freed in the 1960s. The NFD ones joined their cousins in Tana River county. The ones in Somalia became "Dir".
Show us sources sxbIt comes from the Oromo word Amadu which means Af-madow which was the description of the Wife of the Wardey King. I think she was killed there or something or fell into the well so it was named after her.