CRJ900 Captain reported receiving caution annunciations for hydraulic low pressure; brake pressure and ground spoilers in cruise. Flight crew continued to destination airport and after landing was tugged off runway.

Narrative

Shortly after leveling off in cruise (at 14000) we got a HYD 3 LO PRESS caution; followed within 5-10 seconds by IB BRAKE PRESS and IB GND SPLRS. FO (First Officer) called for the QRH (Quick Reference Handbook); I gave him the plane and radios and started running the HYD 3 LO PRESS. The reservoir was empty; and psi showed 0. After following the step to turn on 3B; we followed up with turning off the 3 A&B pumps as directed; did the several steps of prepping for landing (grnd prox flap override and N/W steering off); then stopped to discuss quickly and I (Captain) [requested priority handling]; stated our plan to continue to ZZZ; told ATC the time/souls/fuel on board. We were XX [minutes] out from ZZZ. I checked in with the FO; called the FAs; gave them the [priority handling] briefing; told them it was a moderate level landing; told them we would be stopping on the runway and getting towed in; told them I would be making an edited version of that in an announcement to the pax shortly. Checked in with my FO; plane was flying fine (as we would expect based on hyd 3 not being as needed for inflight controls). Made a PA to the pax telling them a backup braking system had malfunctioned; we have two other braking systems; but because of the system not working we would be stopping on the runway and getting towed in. Told them because we were doing a less normal landing that fire trucks would be there and I expected them and that's not a cause for worry. Told them the crew trains on this maintenance scenario and we would be landing in XX [minutes]. Came back and took the radios from the FO. Told him I would be stealing his landing. We reviewed fuel; how much time we had; sent messages to dispatch telling them we [requested priority handling] and asking them to coordinate the tug to bring us in. FO and I did the landing math multipliers based on runway conditions; told ATC we would be taking [Runway] XXR (longest runway; currently in use for takeoffs). ATC tried to give us a descend via clearance and we declined it; told them to give us delay vectors and we needed XX [minutes] to finish prep. They kept trying to turn us in early and we said no; we are still prepping. Told them we would be stopping on the runway and getting towed off. Set up the landing numbers; added the +12 to Vref; briefed the approach (mostly visual but shot an ILS through the highish ovc). We switched roles and I became PF. Read through the QRH in entirety again to make sure we'd planned for all the steps. Talked about what we would do if the gear didn't come down and lock (go around; not touch the gear handle; go to flaps 8; get delay vectors while the FAs briefed the cabin for a red level/emer landing; verified we had lots of fuel to do all of this). Talked about the mechanics of the brake accumulator system and that I would do one brake application and use thrust reversers til full stop instead of stowing them at 60 kts. Did our descent and approach checklists. Ran the end of the QRH (limited to flaps 20) coordinated with low level approach control on what our final speed would be and which fix we wanted to get turn on for- ZZZZZ). told ATC we were ready; got turned in; ran end of QRH; FO pulled the manual gear extension. gear dropped; mains locked in quickly; nose gear took longer- we were happy when that locked in. Shot the ILS; got visual; had a very nice landing if I can toot my own horn and came to a stop on the runway. Tower talked with us and then gave us a discrete frequency with ARFF (Airport Rescue and Firefighting). ARFF talked with us; we asked for a condition report. I made a PA to the pax telling them we were stopped and that a fire truck was doing an exterior inspection; and that they needed to stay seated til we got tugged in to the gate. ARFF circled the plane; told us they could see a leak on the nose gear but we looked good. They asked if we wanted to be accompanied to the gate and we said yes. Tug showed up; weren't on frequency. One of the drivers came so close along my side of the plane I could barely see him and then kept poking his index finger into his palm. Not the sign we are trained on for for door open. Didn't plug in a head set; didn't try to communicate with us. Guy just opened the door with both engines running. FO and I were about to start shutting things down after talking with ARFF and doing pax PAs. I was very unimpressed. Tug guy came up; didn't talk to me (Captain) and I had to go off the plane and walk over to the tug (FO is shutting things down). They were unwilling to talk much and were very dismissive. Had to directly ask how they were going to capture us and the plan for towing us in. Arranged all that and we got towed in; ARFF followed us to the gate and we thanked them. Mechanic came up the airstairs and asked us a few questions. Told him I needed to stand at the door and thank the Passengers as they got off and then we could debrief. Passengers were calm; many of them thanked us. Once the pax were off; the FAs were met by their Manager and FO & I were talking with the Mechanics. An Assistant Chief Pilot came up to meet us. I thanked the FAs; checked that they were ok (they wanted to go catch their commutes); they left. We debriefed with the Mechanics; wrote up the maintenance issue in the logbook and called our duty pilot. Cause: Leaky hydraulic system.Suggestions: Not really preventable. Our maintenance people work hard to take good care of us; and mechanical systems break. I would like the tug crew to use the available tools to communicate with us properly prior to opening doors with engines running.