# Scenario ROI Assumptions (Auditable, Range-Based)

## Scope
Planning-level scenario model for a **10 MAF/year** capture-treatment-injection portfolio under three hydrologic states:
- **Normal**
- **Drought**
- **Megadrought**

All values are in **2026 USD** and should be treated as **modeled scenario outputs**, not measured historical facts.

## Core Financial Inputs (Modeled)
- CAPEX range: **$114B (low) / $224B (base) / $434B (high)**
- Annual OPEX at full deployment: **$9.0B / $18.2B / $36.0B**
- Discount rate: **5.0% real** (sensitivity at 3.5% and 7.0%)
- Design life: **30 years**
- Ramp-up: **5 years**

## Scenario ROI Summary (Modeled)

### 1) Normal
- Net annual benefit: **$13.0B / $3.8B / -$14.0B** (low/base/high)
- Benefit-Cost Ratio: **1.46 / 0.83 / 0.49**
- Interpretation: highly sensitive to execution discipline and cost control.

### 2) Drought
- Net annual benefit: **$55.0B / $45.8B / $28.0B**
- Benefit-Cost Ratio: **3.92 / 2.35 / 1.07**
- Interpretation: avoided-loss value dominates as supply stress rises.

### 3) Megadrought
- Net annual benefit: **$133.0B / $123.8B / $106.0B**
- Benefit-Cost Ratio: **9.44 / 6.98 / 4.06**
- Interpretation: behaves like infrastructure + catastrophe insurance.

## Formula Skeleton
`Annual Net Benefit = Gross Scenario Benefit - Scenario OPEX`

`Simple Payback = CAPEX / Annual Net Benefit` (when annual net benefit > 0)

`BCR = PV(Benefits) / PV(Costs)`

## Measured Inputs Used to Constrain Scenarios
- USGS groundwater decline/depletion context
- NOAA drought and climate trend records
- Public water-system and agricultural stress signals from federal datasets

## Explicit Caveats
- This is **not** a deterministic forecast.
- Values are sensitive to permitting timelines, treatment requirements, energy prices, and hydrogeologic constraints.
- Report as ranges and confidence levels, not single-point certainty.

## Linked Data Artifact
- `/research/investment-scenario-roi.json`