Date: 201909
Local time of day: 1201-1800
Location: VNY.Airport, CA
Aircraft: Small Aircraft
Operator: Personal
Operating under: Part 91
Flight plan: VFR
Flight phase: Taxi
Airspace: Class D VNY
ATC / advisory: Tower VNY
Second aircraft: Medium Large Transport; Low Wing; 2 Turbojet Eng
Reporter organization: Government
Reporter function: Local
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Communication Breakdown; Situational Awareness; Workload; Time Pressure
Anomaly: ATC Issue All Types; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Incursion Runway
Detector: Person Air Traffic Control
When detected: In-flight; Taxi
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Executed Go Around / Missed Approach
Contributing factors: Human Factors; Procedure
Primary problem: Procedure

Narrative: VNY currently has a single runway RWY 16R. RWY 16L is closed due to construction [on nearby taxiways]; and is temporary taxiway Tango. I was in the middle of a training session that I had to take over because the traffic volume had exceeded the CPC-IT's current level. Ground Control had requested multiple times to cross a tug escorted by airport operations that needed to cross RWY 16R twice due to restrictions for jets on temporary taxiway tango.There were multiple VFR aircraft waiting to depart along with 4 IFR departures waiting at the end. 6 inbound VFR aircraft and a string of IFR arrivals approaching. We had requested SoCal to pull two aircraft out of the arrival sequence because there were 5 aircraft already sequenced to land and spaced out for a little more than minimum runway separation. And there was no room for the first two jets.While we were in recovery mode SoCal called the tower on the tower phone to ask us why we were not accepting aircraft; and added to the complexity and frustration to an already hectic situation. With a single runway and busy traffic SoCal does not provided us with adequate spacing to accommodate VFR. There are restrictions to having 7 miles of in-trail spacing and a speed restriction of 170 kts; however a majority of IFR aircraft on a busy Sunday afternoon will be given the visual approach alleviating the need to put in spacing and speed restrictions.While still in recovery mode we were able to get some of the crossings accomplished and was able to begin getting some of the departures out. When Aircraft Y was on a mile final and Aircraft Z was on a 5 mile final; (I had to slow both of the arrivals down) I asked Aircraft X what their departure request was. They responded right crosswind. I then asked them if they can take an immediate with the intention to use LUAW after Aircraft Y passed. I canceled Aircraft Z's landing clearance and advised them that Aircraft X would be going into position and departing prior to their arrival.Multiple people in the tower; including myself; noticed Aircraft X emerge from behind an IFR [departure] holding short of RWY 16R. Aircraft Y was over the VOR north of the field. Aircraft X crossed the hold bars; and I said on frequency 'No; no; no...' Aircraft X stopped prior to the runway edge line. I gave Aircraft Y go-around instructions and pattern altitude 2;000; prior to reaching the airport boundary. I then put Aircraft X in position and departed them on a right crosswind. Then cleared Aircraft Z to land.Aircraft A was entering the right traffic pattern from the Southwest. Aircraft Y at the approach end offset to the right. I immediately instructed Aircraft A to make a left 360 immediately; and called the Aircraft A traffic to Aircraft Y and to turn to the downwind. There was additional traffic inbound to BUR on the RWY ILS that crosses over the VNY airport at midfield. I noticed Aircraft Y climbing through 2;220 I then immediately called the BUR traffic that was at 3;200 and reiterated that the pattern altitude was 2;000. I then sequenced Aircraft Y to follow Aircraft Z.I could have waited 10-15 seconds to ask Aircraft X if he could take an immediate departure which Aircraft Y would have been closer and more apparent; but I was trying to pre-plan to know if I could get Aircraft X out for departure between the two [jets].When VNY is in a single runway operation; do not allow a workaround to not require the spacing and speed restriction to IFR jets.SoCal should not blindly prioritize IFR aircraft over VFR aircraft that have been waiting to arrive VNY. They continue to slam visual approaches with 3 or 4 VFR aircraft on final already and no space to put the IFR which often times ends with a VFR aircraft being sent around.




Synopsis: VNY Tower Controller reported separation and runway issues relating to a runway closure at Van Nuys airport.