CRJ700 Captain reported a hydraulic failure and subsequent loss of nose wheel steering while taxiing to the gate. The aircraft was subsequently towed to the gate.

Narrative

Approach; landing; and landing rollout were all normal. I exited the Runway via two left turns. Whilst taxiing straight ahead towards the Terminal Ramp; I noticed the plane responded with a slight hesitation upon using the steering tiller to maintain the nose gear on the Taxiway line. I remarked to my First Officer about it. Soon after we received a hyd system 3 caution message. I selected the hydraulic synoptic page. And noted the system quantity was down to zero percent. I informed Ground we would need to stop on the Taxiway. I ordered my First Officer to complete the QRC and QRH for Hyd sys 3 caution message. I coordinated with ATC; operations; and dispatch that we would need a tow in. We then were towed in by our ground personnel. The only issue noted with the tow in was that the nose wheel was slipping a little bit in the tugs claw due to the hydraulic fluid acting as a lubricated on the tire. I asked the tug driver to go slow and to inform me if at any moment he wouldn't be able to complete the tow. We arrived at our gate with no further issues. A possible old or worn part or tubing might have been the cause. A bulletin could be issued to better help pilots with the same issue in the future to understand the necessary steps to be taken for dealing with hydraulic fluid spillage on ramps; aircraft; and taxiways.