The San Joaquin County Board of Supervisors will conduct a public hearing Tuesday to consider extending an interim urgency ordinance that would prohibit the flooding of agricultural land in the Delta in manners considered inconsistent with common practice. One year ago, supervisors adopted a 45-day emergency ordinance prohibiting flooding in the Delta. At the end of the 45 days, the board granted an initial extension to last 10 months and 15 days, according to Tuesday’s agenda.