Bioregional multi-member district

A bioregional multi-member district voting system is a form of single transferable vote used in allocating seats in a legislature or votes on a council of some body representing a physical place/region.

Versions with fractional or partial members) also involve a mixed proportional representation round that is conducted after the STV round, to ensure fairness to those parties that are locked out in the STV round but receive above a certain threshold of the popular vote:

As an electoral reform it achieves three sets of advantages:
#the bioregional democracy advantages of representation by bioregion, an end to gerrymandering and extreme stability since borders are set by biological criteria, e.g. watershed
#the single transferable vote advantage of no wasted votes - every vote counts once and only once and preferences are expressed directly on the ballot; in single-member elections (such as for Mayor) the system gracefully devolves to instant runoff voting using the same ballot exactly
#the mixed proportional representation advantages that every party leader above a certain threshold of popular vote will receive a seat in the legislature, and (depending on the specific variant of the system), so may other members on a party list or who were unsuccessful in the STV round but received a high popular vote