Refreshingly Rational -- Iowa's Redistricting Process
An Example of the Right Way to Draw Legislative Districts
...the nonpartisan Legislative Services Bureau starts the process. The Bureau must develop up to three plans that can be accepted or rejected by the legislature.
The four criteria for the Bureau's plans, in descending order of importance, are:1 - population equality,Chapter 42 specifically forbids the use of political affiliation, previous election results, the addresses of incumbents, or any demographic information other than population in creating the redistricting proposals.
2 - contiguity,
3 - unity of counties and cities (maintaining county lines and "nesting" house districts within
senate districts and senate districts within congressional districts), and
4 - compactness.