A gate that passes water when closed wastes discharge continuously and erodes the downstream floor. Leakage usually starts at the seal seat, not at the leaf: distorted seat faces, worn rubber and a frame that was never grouted true.

Rising-stem spindles buckle when the closing thrust exceeds their slenderness limit, or bend when the leaf jams on one side. The gate then cannot be lifted at the exact moment a regulator setting must change.

Indus water carries a heavy silt load. Abrasion wears seal seats, guide grooves and pump internals — first showing as increased leakage, then as loss of alignment and rising operating effort.

Many gates are lifted twice a year. Between operations the stem thread corrodes, the nut galls and the guides pack with silt, so the gate refuses to move during a closure window that lasts days, not weeks.

Alternate wet and dry zones at the water line corrode fastest. Poor surface preparation makes any paint system fail early — the coating lifts, the section thins, and the leaf loses stiffness.

Floating weed, plastic and crop residue choke intakes, block outlets and jam gate grooves. A blocked screen also raises differential head across the rack, which can collapse an under-designed one.

Unlined watercourses and leaking outlet structures lose a large share of the delivered discharge before it reaches the field, and the loss falls hardest on tail-end farmers.

When the outfall rises, water flows back through the drainage line and floods the area the system was built to protect. Flap gates that are warped or silted simply do not seat.

Lift and tubewell pumps run with a falling water table and sand in suspension. Insufficient NPSH and abrasive sand destroy impellers and bowls within a season.

Structures built decades ago carry gates for which no drawing survives. Imported replacements do not fit the embedded frame, and re-casting the whole structure is not an option.