Guntur district's official profile identifies the old Krishna ayacut now associated with Prakasam Barrage. This is a Krishna river headwork near Vijayawada, distinct from the person Tanguturi Prakasam and the present Prakasam district. A name can refer to a structure, a historical figure or a district; the exam noun determines the answer. A barrage raises and controls water for diversion, while a large storage reservoir is designed around a different primary function.

The delta's canals help serve agricultural land on more than one side of the river. A map point at Vijayawada is a headwork marker, not the outline of the irrigated command. A candidate should also avoid moving the barrage to the Godavari because both rivers support AP paddy. The correct pair is Prakasam Barrage–Krishna. If an item asks its current storage or discharge, look for a dated government operational report rather than a static map.

Worked example: Prakasam Barrage crosses the Krishna near Vijayawada and helps divert water into delta canals. Its name is a common exam clue, but the barrage is not a crop or a river basin. If an image shows gates across a river, ask whether the question asks the structure, river, city or beneficiary command. Each is a separate label.

Active recall: State the river, broad location and main diversion role of Prakasam Barrage.