Select a parameter card to view its W-state thresholds, derivation method, and references.
Water is assessed separately from the land and reported alongside it — never inside it. Fifteen parameters across five groups establish source type, sustainability trajectory, quality constraints, delivery cost, and basin allocation ceiling for every site in the Kingdom.
Select a parameter card to view its W-state thresholds, derivation method, and references.
The source never disqualifies land on its own. Only the trend does. Drawing on ancient water is reported, not forbidden — most of the Kingdom’s agriculture already does it. What disqualifies a site is a water table falling fast enough that it will not outlast the investment placed on top of it.
The trend state is governed by WP-B-01 (Water-Level Trend) interpreted through WP-B-02 (Aquifer Type). Thresholds are per-aquifer, not national.
| Code | Source Type | Level Holding WP-B-01 State 1 |
Falling Slowly WP-B-01 State 2 |
Falling Fast WP-B-01 State 4 |
|---|---|---|---|---|
| WR | Renewable groundwater Refills from rainfall on a human timescale |
WR1 — Usable | WR2(y) — Monitor | WR4(y) — Not Usable |
| WF | Fossil groundwater Ancient water — does not refill. Reported, not forbidden. |
WF2 — Use, report | WF2(y) — Horizon calc | WF4(y) — Not Usable |
| WM | Mixed groundwater Partially renewable, partially finite |
WM2 — Monitor | WM3(y) — Conditional | WM4(y) — Not Usable |
| WT | Treated wastewater Non-depleting — level trend not applicable |
N/A — Level not applicable | N/A | N/A |
| WD | Desalinated supply No aquifer involved — level trend not applicable |
N/A — No aquifer | N/A | N/A |
| WS | Surface water & harvesting Seasonal — trend based on dam storage and wadi flow records |
WS2 — Seasonal | WS3(y) — Declining flows | WS0 — Potential only |
| Example Code | Reads As | What It Means for the Site |
|---|---|---|
| WR1 | Renewable groundwater — State 1 | Usable now. Stable level, within reach, sufficient volume. No constraint on drawing on it. |
| WF2(y) | Fossil groundwater — State 2, sustainability constraining | Usable but slowly depleting. Horizon calculation required. Use with eyes open. |
| WF4(y) | Fossil groundwater — State 4, sustainability stops it | Not usable: falling too fast for the investment to outlast it. The land capability is unchanged. |
| WT3(a) | Treated wastewater — State 3, access constraining | Water is there and of acceptable quality; infrastructure to reach the site must be built first. |
| WS0 | Surface water — State 0 | Potential only. Conditions are favourable; no developed supply exists yet. Counts as a route that investment could open. |
| WF4(y) · WT3(a) · WS0 | Three sources, three states | No usable water today. Two routes exist that could change that: connect to treated wastewater network, or develop surface harvesting. This is a planning finding, not a dead end. |
Every hectare can pass the water test individually, and the basin can still run dry. The water beneath a hectare is shared with every other hectare above the same aquifer. This diagram shows how the basin ceiling converts a site-level finding into a basin-level plan.
Zones C and D are capable land waiting on water — not failed assessments. The gap between the capable area bar and the basin ceiling is the size of the prize the country cannot currently claim. It is exactly what more water from reuse, desalination, or efficiency would unlock. The ministry sees both the ceiling and the opportunity below it.
Water assessment parameters and thresholds are grounded in internationally recognised UN/FAO parameters. ECw, SAR, chloride, and boron thresholds follow FAO Irrigation and Drainage Paper 29 Rev. 1 (Ayers & Westcot, 1985). Volume and crop water demand calculations follow FAO Irrigation and Drainage Paper 56 (Allen et al., 1998). National water statistics carry their sources and should be confirmed against the current MEWA position before external publication, as published figures vary between sources by up to a factor of three.
What this module does not decide: The assessment does not decide whether the Kingdom should spend a finite aquifer. That is a national policy question about how much of a non-renewable resource one generation may use. What it does is make the choice visible: which land depends on which kind of water, how long that water is expected to last at the rate a development would imply, and how much capable land each basin can actually support. The decision stays with the ministry. The evidence for it comes from here.