Tower Controller in Charge (CIC) reported an airborne conflict when Developmental Controller released an IFR departure having previously approved an opposite direction IFR arrival; and the Instructor did not intervene. Radar Controller took corrective action. Reporter alleges many Developmental Controllers have been given excessive training; wearing down the Instructor corps.

Narrative

I was CIC in the Tower. Ground Control was staffed by a Developmental who had certified on the position the day before. Training was being conducted on the Local Control position for a Developmental who was recently given back all of his hours for training on Local Control and starting from scratch. He has a combined total of over 100 hours of training on the position. I was monitoring all Tower frequencies.Runway 31 was in use and we were advertising the RNAV 31 approach. Local Control approved an opposite direction Localizer Runway 13 approach circle to land Runway 31 by transition from the VORTAC and a full procedure approach from FAF for the BE400. The E135 was taxied out for departure Runway 31 and standard operating procedure is to have jets depart runway heading to 5;000 FT. The OJTI who was on Local Control has over 20 years experience and is a veteran of the facility and I felt he had a handle on the position; so I allowed myself to focus my attention on an issue the Ground Controller was having with updating the current weather conditions in the data display system. My attention was pulled back to the Local Control position when Radar called to tell Local Control that they were turning the E135 to avoid the BE400.At that point I looked at the D-BRITE and realized that the E135 had been given a takeoff clearance in accordance with the SOP; but in direct conflict with the BE400. When I realized what had happened the BE400 and the E135 were diverging and more then 1;000 FT vertically separated; but I assume standard separation had been lost prior to that. Over the past year several Developmental's training at the facility has trained completely through their hours; failed to certify; then were given complete do-overs in their training by recycling all or some of their hours. This has worn out almost all of the OJTI's and faith has been lost in the system. In turn; many of the OJTIs aren't able to provide the amount of attention that is needed toward training and service is degraded at the facility. Also; adequate training is not being conducted on how to make weather observations. In order to prevent this event from reoccurring; I will not allow myself to be distracted with lower priorities; and will provide first priority to separating aircraft and issuing safety alerts. I will also try to not be complacent when monitoring a veteran controller.