SMT X ATTEMPTED TO LAND ON CLOSED PORTION OF RWY.

Narrative

I WAS WORKING LCL CTL AND HAD CLRED SMT X; A BE30 TO LAND ON RWY 19L. THIS IS AN 11500 FT RWY; BUT DUE TO CONSTRUCTION ONLY THE LAST 5050 FT FROM THE RELOCATED THRESHOLD WAS USABLE. MEN AND EQUIP WERE WORKING ALL ALONG THE CLOSED PORTION AND; IN PARTICULAR; CLOSE TO THE RELOCATED THRESHOLD! THE ARPT AUTH IN THEIR INFINITE WISDOM -- HAD CLOSED THE PARALLEL TXWY WHICH REQUIRED BACK TAXI TO EXIT. MANY COMPLAINTS BY THE CONSTRUCTION CREWS WERE MADE TO ARPT OPS CONCERNING LOW FLYING ACFT. I FEEL THIS IS A DANGEROUS SIT AND THAT THE WHOLE RWY SHOULD BE CLOSED. MY BACK WAS TO RWY 19L AS I WAS BUSY WORKING DEPS FROM RWY 19R. SMT X INQUIRED ABOUT WHY YELLOW VEHICLES WERE ON THE RWY. I TURNED AROUND AND SAW THAT HE WAS ABOUT TO FLARE FOR LNDG ON THE CLOSED PORTION OF RWY 19L. I ISSUED AN IMMEDIATE GAR. PLT SAID HE HAD ATIS (WHICH CLRLY STATED CLOSURES) BUT SAID HE WAS CONFUSED BECAUSE OF A L1011 PARKED IN RWY 19L RUN-UP BLOCK. THE CONSTRUCTION CREW COMPLAINED. IAD AREA MGR DID NOT FOLLOW-THROUGH BEYOND GIVING PLT A CAUTION. I FEEL THE RWY SHOULD BE CLOSED ALTOGETHER.