3.1 INTRODUCTION

The primary purpose of a water distribution system is to deliver water to the individual consumer in the required quantity and at sufficient pressure. Water distribution systems typically carry potable water to residences, institutions, and commercial and industrial establishments. Though a few municipalities have separate distribution systems, such as a high-pressure system for fire fighting or a recycled wastewater system for nonpotable uses, most municipal water distribution systems must be capable of providing water for potable uses and for nonpotable uses, such as fire suppression and irrigation of landscaping.

The proper function of a water distribution system is critical to providing sufficient drinking water to consumers as well as providing sufficient water for fire protection. Because these systems must function properly, the principals of their planning, design, and construction need to be understood. This chapter focuses on the critical elements of planning and design of a water distribution system. The information presented primarily discusses typical municipal water distribution systems; however, the hydraulic and design principles presented can be easily modified for the planning and design of other types of pressure distribution systems, such as fire protection and recycled wastewater.