Date: 201911
Local time of day: 0601-1200
Location: ZZZ.ARTCC, US
Flight conditions: VMC
Aircraft: EMB ERJ 140 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Engine Driven Pump
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Human factors: Time Pressure; Distraction; Situational Awareness
Second reporter function: Pilot Not Flying; First Officer
Anomaly: Aircraft Equipment Problem Less Severe
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Landed in Emergency Condition; Flight Crew Overcame Equipment Problem; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: We noted that the HYD1 system fluid level was getting low and then dipped into the orange arc; accompanied by an associated EICAS advisory. This is not an unusual event due to a quirk in this aircraft's hydraulic systems; and initially we simply noted it for [Maintenance Control] to fix once we were on the ground. However; as we continued to monitor it; we noticed the level continued to drop; which is not so usual. As it dipped further into the orange arc of that gauge; we began to review the consequences and options in the event that the HYD1 system actually failed; particularly in regards to getting the gear down. As the level continued to get lower; we decided we needed to simply get the aircraft on the ground as soon as possible; rather than wait for a potentially worse situation and actual emergency to actually develop.Having already notified ARTCC of the developing situation; we decided to err on the side of caution and [request priority handling] that would allow us to fly direct to the airport and land on the closest available runway which was XXR. This entailed a slight tailwind; but well within limits and preferable to spending more time in the air and risking an actual hydraulic failure. Rather than risk running out of fluid pressure for the gear; as we eventually slowed below 250 kts; [and] prematurely lowered the gear while we judged that we still had the pressure and fluid for it. Previous consideration with this was given to how much extra fuel burn this would entail; and we delayed this until well within the adjusted fuel range of the airport. At that point; gear was lowered about 15 NM out; the flight actually proceeded and landed normally without further incident. The FA (Flight Attendant) was kept apprised of the situation but no announcement was ever made to the passengers since nothing developed to a level that warranted making them concerned about their welfare.After parking at the gate; both the CFR (Crash Fire Rescue) Chief and Maintenance reported hydraulic fluid leaking from the number one left engine. Maintenance's initial investigation suggested that the main engine pump had developed a leak.CRM played a crucial role in this event and proved its worth. I want to commend the FO (First Officer); for providing numerous suggestions and feedback as we discussed options and how we may have to deal with various consequences. He was proactive in researching and providing information such as the increase in fuel burn rate due to lowering the gear early. All options and possibilities were thoroughly reviewed and discussed and the decisions made only after thorough consideration. The emergency was; ultimately; only a preventative one; and apart from a [Company] Captain in the back; none of the passengers were any the wiser. Early and preventative action by all the crew not only meant that we were prepared for all contingencies but that we never had to enact any of those scenarios and the flight landed normally before anything any developed into an actual emergency.


Second narrative: [Report narrative contained no additional information.]


Synopsis: EMB-140 flight crew reported a drop in hydraulic fluid quantity in the Number 1 HYD system; later attributed to a leak in the associated engine driven pump.