Problem Statement: Hydraulic Analysis and Design of a Municipal Water Distribution System
Background

The City of Red Bluff, population 6,500, is expanding into newly platted residential subdivisions on the east side of town. The municipal water utility currently serves customers from a single elevated storage tank (EST) and a groundwater well with chlorination. To support future growth, the city must extend its distribution network and verify that the system meets required pressure and fire-flow standards under varying demand conditions.

You have been contracted as a junior design engineer to assist the city in planning and evaluating a proposed network expansion.

Available Information

A base map in QGIS showing:

Existing mains (8-in PVC)

Proposed street alignments

Approximate ground elevations (DEM data)

Locations of existing hydrants and valves

System Facilities:

Groundwater well: 750 gpm supply capacity

Elevated Storage Tank:

Bottom water level = 102 ft above ground

Operating range = 20 ft

Pressure at EST outlet may be assumed as static head only (no pumps for this assignment)

Demand Information:

Existing average day demand: 0.6 MGD

Projected future average day demand: 0.9 MGD

Peak hour factor: 2.5

Fire flow requirement (per state standards):

1,000 gpm for 2 hours at 20 psi minimum residual

Residential zone

Pipe Size Options (assume C = 130):

6-inch

8-inch

12-inch (collector / trunk only)

You may reference:

State design criteria (e.g., Texas Design Criteria Manual)

AWWA recommendations

Local city specification excerpts as provided

Task Requirements
1. System Layout

Using the QGIS base map and reasonable engineering judgment:

Propose a new looping network to serve the planned expansion

Select which pipes must be 6", 8", or 12"

Place at least four fire hydrants

Indicate pressure zone boundaries (single zone in this case unless students choose otherwise)

Output: Annotated map

2. EPANET Hydraulic Model

Build the extended system model including:

All existing mains

Proposed pipes

Estimated nodal demands (may assume uniform assignment or allocate proportional to parcel counts)

Required simulations:

Average Day Demand

Peak Hour Demand

Fire Flow Test at the most hydraulically disadvantaged hydrant

3. Performance Evaluation

For each simulation, report:

Minimum and maximum pressures

Nodes below required pressure thresholds

Flow velocity limits (check against 2–8 ft/s guideline)

Whether the fire-flow node meets 20 psi residual

If criteria are not met:

Suggest corrective actions, such as:

Larger mains

Grid looping

Additional storage or booster pumping (concept only)

4. Deliverables

Submit the following:

Annotated QGIS layout

EPANET input file (.inp)

Pressure/flow summary tables

One-page written design justification, including:

Major assumptions

Pipe size reasoning

Identification of weakest node

Whether standards are met and why

Learning Objectives

By completing this project, students will:

Apply hydraulic principles to a real municipal network

Use EPANET for steady-state modeling

Interpret results in the context of state design criteria

Demonstrate the value of looping and pipe sizing

Build GIS-based infrastructure planning confidence

If you'd like, I can provide:
✔ A sample EPANET network (starter .inp)
✔ A rubric or peer-review form
✔ Common “mistakes expected” so you can guide gently
✔ A grading key showing what a compliant vs. failing design looks like

Just say when, Sensei!