Comparison view

/comparison puts the three scenarios side by side. Signing in is required.

Choosing what to compare

A map of the study area sits at the top of the page. Click a WRUA polygon to add it to the selection, or pick one from the dropdown. Selected WRUAs are shown in cyan and as chips beside the dropdown. Selecting more than one aggregates them.

What is reported

Three cards, one per scenario, and a Detailed Comparison table with the same six rows:

Row	Meaning
Total Deficit	Gross annual deficit. Identical in all three columns, on purpose
Deficit Met	What the scenario delivers
Unmet Deficit	What is left over
Ponds Required	Farm ponds the design calls for. Zero under Reallocation only
Storage Volume	Ponds times the 1,000 m³ unit pond
% Deficit Addressed	Deficit Met over Total Deficit

Every volume on this page is m³, not Mm³. So is the underlying /api/compare/<wrua> payload, which states "units": "m3".

Total Deficit is deliberately the same across the three columns: the gross annual deficit is the single denominator, which is what makes the three percentages comparable. Comparing each scenario against its own denominator would make the percentage row meaningless.

Below the cards, Monthly Unmet Deficit by Scenario overlays the three residual series across the twelve months. Lower is better.

Reading a near-zero reallocation result

Reallocation moves surplus by gravity within a WRUA, so it can only meet a deficit where upstream surplus exists. A WRUA with little upstream surplus shows a Deficit Met close to zero. That is the model working, not a fault.

For the same reason, where reallocation offsets little, Reallocation + Storage needs the same number of ponds as Storage only. Where there is more surplus to work with, it needs fewer. Across the whole study area the reduction in pond count from Storage only to Reallocation + Storage is under one percent, because in most WRUAs there is too little upstream surplus for reallocation to remove any pond at all.

Where the numbers come from

Reallocation is read from the reallocation table. Storage and Reallocation + Storage are computed from the 48-step farm-pond simulation, read at its converged year. The payload carries that statement in its own basis field. See the API reference.