The Shabelle does not have enough water to withstand the evaporation losses, the Shabelle valley inside Somalia is also too flat to build a dam.
A dam could be built on the Juba, but losses to evaporation would be very high considering how hot areas like Luuq and Dolo are. The money for a dam at Baardheere would be better used building a Jilib-Dolo road and some canals.
Somalia should buy hydroelectricity from Ethiopia and ask it to coordinate water releases so that Somalia receives a steady flow instead of huge fluctuations.