CRJ200 Captain experiences Flaps Fail CAS message during approach. QRH procedures for flap asymmetry are complied with and an uneventful landing ensues.

Narrative

After being given final heading and altitude outside FAF for the ILS; we began to configure the aircraft for approach. Our attempt to select flaps 8 failed and was accompanied by Flaps Fail amber CAS message and Master Caution. We advised ATC of our difficulty and asked for vectors to allow for ORH procedures and icing avoidance. The First Officer was flying and continued to do so while I completed the QRH. During this time I discovered an asymmetry between the flaps (left flap 3/right flap 4). QRH for flap asymmetry was completed and I requested the longest runway for approach and declared emergency. I contacted company; alerted the flight attendant and advised passengers. Once cleared for the approach I assumed the pilot flying duties. We broke out approx. 3000 msl and continued the approach VMC. Thanks to our training the rest of the approach was uneventful. We touched down approx 1500 feet down the runway and rolled out without over-heating the brakes (no indications greater than 4). Once clear of the runway; we stopped and requested inspection from Fire and Rescue. When cleared; we canceled emergency and taxied to the gate without incident.