Makes failure to maintain a natural stream channel that causes an unreasonable and substantial physical obstruction of the natural flow of water a violation of the State Water Code, with certain exceptions. Establishes a period of time after receipt of written notice of certain violations of the State Water Code during which a violator may remedy the violation or enter into a corrective action plan with the Commission on Water Resource Management (CWRM). Gives CWRM the discretion to impose a minimum penalty per State Water Code violation, increases the maximum penalty per violation, and authorizes CWRM to consider each day that a violation exists or continues to exist a separate offense. Establishes factors CWRM must consider when determining the amount of the penalty. Prohibits the State from acquiring a fee simple interest in any artificial watercourse, including a canal or ditch, under certain circumstances. Allows the State to acquire a fee simple interest in the artificial watercourse if the Legislature provides prior approval by concurrent resolution. (CD1)