Lecture Notes: Creating and Managing Pressure Zones and District Meter Areas

Introduction

• Presenter: Tom Walski
• Topic: Creating and managing pressure zones and district metered areas (DMAs) in WaterGEMS.

Basic Definitions

Pressure Zones

• Definition: Area in a water distribution system with a similar hydraulic grade.
• Separation: Usually separated by pumps or pressure reducing valves (PRVs).
• Purpose: Manages pressure to ensure customers receive appropriate pressure based on elevation.
• Boundaries: Defined by closed valves, PRVs, or pumps.

District Metered Areas (DMAs)

• Definition: Areas where all inflows and outflows are metered.
• Purpose: Used in water audits and water loss control studies.
• Relationship to Pressure Zones: Not all DMAs are pressure zones, and vice versa.

Tools and Software

• WaterGEMS Pressure Zone Manager
  • Used for managing both DMAs and pressure zones.
  • Found in the analysis menu or through a specific symbol.
  • Operates based on the current selected scenario.

Setting Up Pressure Zones

Defining Boundary Elements

• Boundary Elements: Elements that define the limits of a pressure zone.
  • Pipes, isolation valves, PRVs, pumps, etc.
• Customization: Specific pipes can be set as boundary elements by closing them.

Steps to Create Pressure Zones

1. Identify Pressure Issues: Use color coding to identify areas with high or low pressure.
2. Install Control Elements:
   • Install PRVs in high-pressure areas.
   • Install pumps in low-pressure areas.
3. Configure Elements: Set PRVs to desired pressure settings and close isolation valves as needed.
4. Visualize Zones: Use the Pressure Zone Manager to visualize and verify zones.

Creating District Metered Areas

Isolating DMAs

• Use PRVs or pumps to clearly define pressure zones.
• Install General Purpose Valves (GPVs) as surrogates for water meters.
• Use a "sleeper PRV" for emergency bypasses.

Analyzing DMA

• Use the Pressure Zone Manager to identify boundaries and properties of DMAs.
• Utilize flow balance tools to understand demand and flow dynamics.

Practical Application

Example Water Distribution System

• Source Location: Southwest corner.
• Pressure Management:
  • PRVs and pumps used to manage high and low-pressure regions.
  • Zones created to maintain desired pressure levels.

Simulation and Analysis

• Pressure Zone Manager Tool: Analyzes system and visualizes pressure zones.
• Flow Balance: Provides demand data and pressure ranges for each zone.
• Extended Period Simulation (EPS): Used to understand cumulative water usage over time.

Conclusion

• Pressure zones and DMAs are crucial for effective water distribution management.
• Tools like WaterGEMS can assist in planning, managing, and analyzing these zones to ensure efficient water use and identify potential issues.

Note: Future presentations will cover detailed procedures for creating pressure zones and DMAs.