How often are precinct boundaries re-drawn?

There is no set limit on how often this can be done. For practicality’s sake it is usually only done shortly after redistricting. However, if a precinct suddenly becomes very over-populated due to new development, the County Clerk must divide that precinct into multiple precincts to maintain fairly equal numbers in the precincts. There are statutory limitations on how many registered voters may be in a precinct.