Sunday Nation: When you talk about all that divides Kenya, the list is long. But one thing should unite the nation during this year of drought and short food supplies: A strong and vibrant water policy. Without it, no democracy can survive. No food can grow. No human can live. During my last trip to Kenya, I was stunned by what’s happening to Lake Victoria. It is shrinking, threatening electrical power along the Nile. Fish are moving far from the shore. Vines are strangling the ports. …