EMB-145 First Officer reported observing a hydraulic fluid leak during preflight. During approach to destination airport a hydraulic pump failed and aircraft was towed to gate after clearing runway.

Narrative

We arrived to the aircraft in ZZZ to operate Aircraft X to ZZZ1. The inbound crew had already departed the aircraft.During my walk around; I noticed a small splash of liquid by the nose gear on the walk around. I further inspected the nose gear and compartment to find nothing leaking; dripping; or abnormal. I then checked the hydraulics compartment and found normal pressure and indications. I took a picture of the fluid on the ground and showed the captain; explaining what I saw. He went out to inspect as well to find nothing out of the ordinary. He mentioned when checking the logbooks he saw a hydraulic fluid transfer performed recently so advised to keep an eye on the fluid levels which were in the green range and hadn't moved during startup; boarding or taxi out. I was PF. Departure was normal. During climb out the captain noticed a decrease in the hydraulic system 1 level to the amber range as the HYD SYS 1 low quantity message appeared on the EICAS. We pulled out and ran the appropriate QRH checklist. We proactively briefed the HYD SYS 1 FAIL checklist as well in anticipation of losing the remaining fluid. We contacted Maintenance and dispatch to advise them of our situation. The captain also advised the FA of the possible situation and kept her in the loop throughout the flight. We slowed to 240 knots to avoid over speeding the aircraft in case of failure. We contacted ATC to advise them of our speed and potential system failure. We requested [Runway] XXR for landing for maximum runway length. We also requested to be taken off the STAR to avoid any issues with speeds or crossing restrictions. We continued to monitor the hydraulic system levels to see HYD SYS 1 quantity consistently decreasing. We briefed the arrival; landing; and taxi in normally as well as if we eventually ended up landing with HYD SYS 1 failed. We were on vectors to final when we received the HYD SYS PUMP 1 Fail and HYD SYS 1 FAIL messages. We advised ATC we would need vectored off the approach. They provided us vectors and declared us a [priority handling] aircraft at that time. We transferred the controls to the captain to complete the flight as PF. We were running the appropriate QRH checklists when the HYD SYS 1 came back on. We were at the point in the checklist for gear extension ; we decided to first try a normal gear deployment with the system back on. The gear came down; locked and indicated correctly; we finished the rest of the QRH and briefed the landing assuming the hydraulic system could fail on us again at any point. We landed without issue and turned off using rudder authority. We received the HYD SYS 1 FAIL again as we taxied off. We simply stopped the aircraft on [Taxiway] 1 as we had briefed for a landing with HYD SYS 1 FAIL to wait for an inspection and tow. We had previously advised the possible need for a tow in. We briefed to stop on 1 to avoid airport congestion to be inspected and towed in. The captain acknowledged the presence of the emergency equipment while we were on the ground and assured the passengers of safety but informed them of our situation and the delay to get to the gate. We complied with airport ops; the tow team; and Maintenance to secure the aircraft and tow into the gate with no damage or injuries.The crew debriefed the situation and thought good CRM and proper training were used in flight to effectively and efficiently deal with the system failure. Precautions were taken to prepare for and setup for a successful landing and tow in. In discussion; the crew could have looped in maintenance on preflight discussions to get additional opinions; more information; and possibly monitor; identify; or alert any indications of hydraulic issues.