**Xuan Khoa Bui, Malvin S. Marlim and Doosun Kang \***

Department of Civil Engineering, College of Engineering, Kyung Hee University, Gyeonggi-do 17104, Korea; khoabx@khu.ac.kr (X.K.B.); malvinmarlim@hotmail.com (M.S.M.)

**\*** Correspondence: doosunkang@khu.ac.kr; Tel.: +82-31-201-2513

Received: 28 February 2020; Accepted: 27 March 2020; Published: 1 April 2020

**Abstract:** A water distribution network (WDN) is an indispensable element of civil infrastructure that provides fresh water for domestic use, industrial development, and fire-fighting. However, in a large and complex network, operation and management (O&M) can be challenging. As a technical initiative to improve O&M efficiency, the paradigm of "divide and conquer" can divide an original WDN into multiple subnetworks. Each subnetwork is controlled by boundary pipes installed with gate valves or flow meters that control the water volume entering and leaving what are known as district metered areas (DMAs). Many approaches to creating DMAs are formulated as two-phase procedures, clustering and sectorizing, and are called water network partitioning (WNP) in general. To assess the benefits and drawbacks of DMAs in a WDN, we provide a comprehensive review of various state-of-the-art approaches, which can be broadly classified as: (1) Clustering algorithms, which focus on defining the optimal configuration of DMAs; and (2) sectorization procedures, which physically decompose the network by selecting pipes for installing flow meters or gate valves. We also provide an overview of emerging problems that need to be studied.

**Keywords:** clustering; district metered area; network sectorization; water distribution network; water network partitioning
