Northeast Tarrant County
From The RadioReference Wiki
As of 10/1/2010 the cities of Colleyville, Keller, and Southlake are sharing dispatch operations. For the police, here's what I've been able to figure out about unit numbers.
1##s Colleyville
2##s Southlake
3##s Keller, which also patrols Westlake
It sounds like the 2nd digit will be the shift for most of the patrol units.
18# Colleyville School Patrol
7## Southlake School Patrol
This is important to know now, because they are all on PATRL1.
C-PATRL1, S-PATRL1, and K-PATRL1 are patched as the primary Patrol channel.
C-PATRL2, S-PATRL2, and K-PATRL2 are patched as the records check/NCIC channel.
C-PATRL3, S-PATRL3, and K-PATRL3 are patched as the traffic channel.