567—71.2(455B) Channel changes. Approval by the department for the construction, operation, and maintenance of channel changes shall be required in the following instances.
	71.2(1) Rural areas. In rural areas:
	a. 	Channel changes not otherwise associated with road projects in or on the floodway of any stream draining more than 10 square miles at the location of the channel change.
	b. 	Channel changes associated with road projects in or on the floodway of any stream draining more than 10 square miles at the location of the channel change whereby either (i) more than a 500-foot length of the existing channel is being altered or (ii) the length of existing channel being altered is reduced by more than 25 percent.
	71.2(2) Urban areas. In urban areas channel changes on any river or stream draining more than 2 square miles at the location of the channel change.
	71.2(3) Protected streams. Channel changes at any location on any river or stream designated as a protected stream pursuant to division III of 567—Chapter 72.
	71.2(4) Channel change by drainage district. Rule 567—72.2(455B) applies to channel changes sponsored by a drainage district. However, approval is not required for repair and maintenance of a drainage district ditch as defined in 567—70.2(455B,481A) if the drainage area of the ditch at the location of the proposed work is less than 100 square miles.
This rule is intended to implement Iowa Code section 455B.275.