Scenarios

Expansion options, capacity triggers, and future possibilities

Capacity Expansion

The Texas Water Backbone is designed for growth. Initial capacity can expand through:

Phase Expansion

PhaseCapacityTrigger
Initial300,000 AF/yrProject completion
Phase 2400,000 AF/yr80% utilization reached
Phase 3500,000 AF/yr80% of Phase 2
Dual Pipeline750,000+ AF/yrLong-term demand

Brackish Integration

Adding inland brackish desalination plants increases total system capacity:

ConfigurationSeawaterBrackishTotal
Base500,000 AF—500,000 AF
With Gulf Coast Aquifer500,000 AF84,000 AF584,000 AF
Full Brackish Build-out500,000 AF234,000 AF734,000 AF

Brackish sources also reduce average system cost (brackish desal is cheaper than seawater).

Demand Triggers

Expansion decisions are based on objective metrics:

Primary Trigger: Utilization Rate

  • Below 60%: No expansion needed
  • 60-80%: Begin planning next phase
  • Above 80%: Initiate expansion construction

Secondary Triggers:

  • Population growth exceeding projections
  • New major industrial/commercial users
  • Regional drought conditions
  • Municipal contract requests
Built-in flexibility: The TBA can respond to demand signals without requiring new legislative authorization for each expansion phase.

Alternative Configurations

2-Pipe vs. 3-Pipe Backbone

A third pipeline could be added for:

  • Higher capacity: 750,000+ AF/year
  • Product differentiation: Separate industrial-grade water
  • Redundancy: Any single pipe can be offline for maintenance
ConfigurationCapacityCapital CostCost/AF
2-Pipe500,000 AF$11.15B$22,300
3-Pipe750,000 AF$15.2B$20,267

The 3-pipe option delivers lower per-unit costs at higher total investment.

Alternative Routes

The proposed route is optimized for:

  • Shortest path to major demand centers
  • Existing corridor availability
  • Terrain and pumping requirements

Alternative routes could serve:

  • Austin/San Antonio corridor (branch line)
  • Houston supplemental supply (shorter segment)
  • West Texas connections (long-term)

Long-Term Vision

2050 and Beyond

As Texas grows toward 55+ million residents, the Backbone could evolve into:

Regional Water Grid:

  • Multiple desalination sources (Gulf Coast + inland brackish)
  • Interconnected pipeline network
  • Regional storage facilities
  • Smart water management systems

National Model:

  • Texas proves the concept
  • Other drought-prone states adopt similar approaches
  • Federal support for water infrastructure grows
  • Texas expertise becomes exportable asset

Climate Adaptation

The Backbone positions Texas for climate uncertainty:

  • Drought resilience: Ocean water doesn’t depend on rainfall
  • Storm resilience: Distributed ASR storage buffers disruptions
  • Flexibility: System can adapt to changing conditions

This is infrastructure for the Texas of 2070, not just the Texas of today.