One of Jerry Brown’s biggest failures as governor has been his stubborn, foolhardy approach to the Sacramento-San Joaquin Delta that provides a portion of the drinking water for 25 million Californians, including more than 5 million South Bay and East Bay residents. The news Friday that the Brown administration is reportedly scaling back his $17 billion, twin-tunnel plan to a single tunnel at slightly more than half the cost is a relief for Northern Californians fearing a massive Southern California water grab at the expense of the health of the Delta.