Adel Hagekhalil is an inspired choice to be the next general manager of the Metropolitan Water District of Southern California, the agency that delivers the water ultimately used by half of the state’s population. He’s an engineer, a consensus builder and a champion of the movement to integrate management of different types of water — drinking water, wastewater, stormwater, environmental water — in order to reduce costs and use precious resources more efficiently. He may be exactly what the MWD needs at this point in its history, as it struggles to redefine itself as a supplier of liquid assets not just from distant mountains and rivers, but from recycled urban wastewater.