COEQWAL summary brief · strategy
Download PDFA summary brief reporting modeled outcome levels for one management strategy, read across the five hydroclimates. Each difference from the baseline is split into the hydroclimate effect and the management effect. Run identifiers for every scenario are listed in the references note.
Summary. This brief reports modeled outcome levels for the current USBR operations without TUCPs strategy: all nine key outcomes under each of the five hydroclimates in the COEQWAL library. Figure 1 places every result beside the baseline, current operations under the historical hydroclimate, and splits each difference into the hydroclimate effect and the management effect. The table beneath the figure gives the same values as numbers, and the companion data file holds all of them. Cells outlined in the table are those where the two effects run opposite ways; the largest such offset is Freshwater for in-Delta uses under extreme climate stress, where the hydroclimate effect is +1.4 and the management effect is −0.6.
This brief reports modeled outcome levels for the current USBR operations without TUCPs strategy, one of 28 management strategies in the COEQWAL library. It covers all nine key outcomes across all five modeled hydroclimates. Every strategy has a brief of this form, built around that strategy’s results. A scenario is one strategy under one hydroclimate; the five hydroclimates are a sample of stress levels, not a forecast, and the hydroclimates reference brief describes how they were built.
Against current operations, this strategy differs in two of the eight operational settings the COEQWAL library records: TUCP actions — Not active; BiOps — 2024 USBR Alt2v1. For the full configuration, see the current USBR operations without TUCPs strategy brief.
Each mark in Figure 1 is the outcome level of one key outcome under one hydroclimate. Each key outcome has its own baseline value, from 1.7 to 4.2; it is the first column of the table. Each difference from the baseline is drawn as two arrows. The warm arrow is the hydroclimate effect: how much current operations under that hydroclimate differ from the baseline. The blue arrow is the management effect: how much the strategy differs from current operations under the same hydroclimate. The two add to the difference from the baseline; a flat tick is a change smaller than 0.1.
Values sit on a continuous axis from 1 to 4.99 with Level 1 (Optimal) at the top, and the shaded bands are the four levels. A positive effect moves a value toward Level 4 (Critical); a negative effect moves it toward Level 1 (Optimal). A key outcome’s value is the unweighted mean of its locations, from one to 132 of them, so a mark can sit close to the baseline even when the locations behind it differ in both directions; the table ‘Locations behind the means’ shows how many differ, and in which direction. How the split works is explained in Separating the effects of strategy and hydroclimate in COEQWAL results; the scale, thresholds, and rounding rules are in How to read the values below.
Each cell reads top to bottom: the hydroclimate effect, the management effect, and the resulting value with its band. The two effects add to the difference between the scenario and the baseline. Outlined cells are those where the two run opposite ways. Readers who want to cite a specific column can link to it directly, and the same numbers appear in the companion data file.
| Key outcome | The baseline | ¶Historical | ¶Moderate | ¶Moderate-high | ¶High | ¶Extreme | Management effect across the five | |
|---|---|---|---|---|---|---|---|---|
| Community surface water | Hydroclimate effectManagement effectValue (level) | L11.7 | 0.00.0L11.8 | +0.2+0.2L22.1 | +0.20.0L22.0 | +0.5+0.2L22.4 | +0.8+0.1L22.6 |
one direction 0.0 to +0.2 |
| Agricultural revenue | Hydroclimate effectManagement effectValue (level) | L22.3 | 0.00.0L22.4 | +0.50.0L22.8 | +0.40.0L22.8 | +0.60.0L22.9 | +0.60.0L33.0 |
no change at the 0.1 threshold 0.0 |
| Environmental flows | Hydroclimate effectManagement effectValue (level) | L33.7 | 0.00.0L33.7 | 0.00.0L33.7 | 0.00.0L33.8 | +0.20.0L33.9 | +0.40.0L44.1 |
no change at the 0.1 threshold 0.0 |
|
Delta estuary ecology single level value |
Hydroclimate effectManagement effectValue (level) | L33.2 | 0.00.0L33.2 | −0.30.0L22.9 | 0.00.0L33.1 | +0.10.0L33.3 | +0.40.0L33.6 |
no change at the 0.1 threshold 0.0 |
|
Winter-run salmon single level value |
Hydroclimate effectManagement effectValue (level) | L44.2 | 0.0−0.2L44.0 | −0.3−0.1L33.8 | +0.40.0L44.7 | +0.60.0L44.9 | +0.5+0.2L44.9 |
crosses zero −0.2 to +0.2 |
|
Freshwater for Delta exports single level value |
Hydroclimate effectManagement effectValue (level) | L22.7 | 0.0−0.2L22.5 | +0.4−0.2L22.9 | +0.6−0.2L33.1 | +1.1−0.2L33.6 | +1.40.0L44.0 |
one direction −0.2 to 0.0 |
|
Freshwater for in-Delta uses single level value |
Hydroclimate effectManagement effectValue (level) | L22.8 | 0.0−0.3L22.5 | +0.3−0.1L33.0 | +0.3−0.1L33.0 | +0.7−0.3L33.2 | +1.4−0.6L33.6 |
one direction −0.6 to −0.1 |
| Reservoir storage | Hydroclimate effectManagement effectValue (level) | L22.4 | 0.00.0L22.3 | 0.0+0.1L22.5 | −0.1+0.2L22.5 | +0.2+0.1L22.7 | +1.10.0L33.5 |
one direction 0.0 to +0.2 |
| Groundwater storage | Hydroclimate effectManagement effectValue (level) | L22.7 | 0.0+0.2L22.9 | −0.1+0.1L22.7 | 0.0+0.2L33.0 | +0.3+0.3L33.3 | +0.5+0.2L33.4 |
one direction +0.1 to +0.3 |
A key outcome’s value is the mean of its locations, so one mean can stand for locations that moved in different directions. The table counts, for each key outcome and hydroclimate, how many of that key outcome’s locations differ from current operations by at least 0.1 on the level scale, and in which direction. To see the data for individual locations, view the Locations of Interest summary briefs.
| Key outcome | Historical | Moderate | Moderate-high | High | Extreme | |
|---|---|---|---|---|---|---|
| Community surface water · 74 | Toward Level 1No differenceToward Level 4 | 8579 | 94520 | 134714 | 133625 | 64325 |
| Agricultural revenue · 132 | Toward Level 1No differenceToward Level 4 | 910122 | 139821 | 910419 | 169125 | 158829 |
| Environmental flows · 17 | Toward Level 1No differenceToward Level 4 | 2141 | 3131 | 1142 | 2132 | 3122 |
| Delta estuary ecology · 1 | Toward Level 1No differenceToward Level 4 | 010 | 010 | 010 | 010 | 010 |
| Winter-run salmon · 1 | Toward Level 1No differenceToward Level 4 | 100 | 100 | 010 | 010 | 001 |
| Freshwater for Delta exports · 2 | Toward Level 1No differenceToward Level 4 | 200 | 200 | 200 | 200 | 020 |
| Freshwater for in-Delta uses · 2 | Toward Level 1No differenceToward Level 4 | 200 | 200 | 200 | 200 | 200 |
| Reservoir storage · 8 | Toward Level 1No differenceToward Level 4 | 431 | 251 | 152 | 134 | 215 |
| Groundwater storage · 42 | Toward Level 1No differenceToward Level 4 | 16422 | 19320 | 16521 | 17322 | 19419 |
Per-location detail and the median difference behind each count are in
the companion data file at #/rows/*/reach.
What does this strategy do? It is described, rather than measured, by a reference brief that carries no modeled results: Current USBR operations without TUCPs strategy brief.
What happens under a different strategy? The same nine key outcomes and the same five hydroclimates are reported once per strategy:
What happens to one key outcome under every strategy? A key-outcome brief transposes this grid — one key outcome of the water system, every strategy, the same five hydroclimates:
How were the five hydroclimates constructed? The hydroclimates reference brief defines them. It reports no results of its own; every brief above is read against the same five.
This brief reports modeled results from the COEQWAL ensemble. It does not predict what will happen, evaluate whether those results are acceptable, or recommend any course of action. The outcome-level framework provides definitional categories; the meaning of those categories for any individual reader, community, or decision is not specified by COEQWAL.
In particular, for this brief: the five hydroclimates are a sample of stress levels, carry no probabilities, and are not a timeline, so no average over them is reported here. Splitting a difference into two effects is arithmetic on modeled values, not a causal claim about the water system, and the two are separable only because each is defined against its own reference. A step or a spread on the level axis is a modeled magnitude, not a benefit or a cost. A key outcome’s value is the unweighted mean of its locations, so locations count equally regardless of the people, acres, or acre-feet each represents, and a location already at either end of the scale cannot move further along it. Locations are modeled nodes, not measured conditions at a place.
A key outcome’s highest value does not necessarily fall under extreme climate stress.
Model runs (this strategy / current
operations): Historical
s0023 / s0020; Moderate
s0136 / s0134; Moderate-high
s0051 / s0047; High
s0060 / s0056; Extreme
s0110 / s0108. The baseline is
current operations under the historical hydroclimate,
s0020.
Build stamp. Snapshot 2026-08-29;
builder version 0.1.0; built 2026-09-25T20:58:30Z;
snapshot data read 2026-08-29; verification: pass. The verification
status is written by the independent check
(briefbuilder.verifier), which recomputes every value in
the companion data file from the per-location data and reads every
arrow on this page, after both files are written. It is not stamped by
whatever produced them.
Companion data file:
scenario_results_brief_current-usbr-operations-without-tucps_schema1.json, holding every value in this brief plus the per-location counts, the
spread measures, the derivation of every number in the prose and the
figure’s declared attribute contract. Per-hydroclimate slices:
Historical #/rows/*/by_hydroclimate/BL; Moderate
#/rows/*/by_hydroclimate/HC4; Moderate-high
#/rows/*/by_hydroclimate/HC1; High
#/rows/*/by_hydroclimate/HC2; Extreme
#/rows/*/by_hydroclimate/HC3. Built from the locked
2026-08-29 API snapshot (api.coeqwal.org v2.1.1 (locked dataset
snapshot)). Decomposition per
Decomposition_Math_Quickref (coeqwal-viz): the
hydroclimate effect is current operations under that hydroclimate
minus current operations under the historical hydroclimate; the
management effect is this strategy minus current operations under that
same hydroclimate. Axis convention [1, 4.99] per
Ordinal_vs_continuous_tiers.md; the visible band is
floor(value). A difference of 0.1 on the level scale is
required before a difference is reported as movement, before a
location is counted as differing from its comparison, and before an
effect prints as anything other than 0.0. Color semantics: warm =
hydroclimate, blue = management. Strategy identity is its descriptive
name; run IDs appear only in this note and the data file.
Every value on this page comes from the outcome-level data, and the data explorer holds the same data without this brief’s selection of it. The link below opens current USBR operations without TUCPs across all five hydroclimates and all nine key outcomes, so a reader can take the comparison apart, add a hydroclimate or a key outcome this brief reports as one number, and read the locations behind a key outcome value directly.
Open current USBR operations without TUCPs in the data explorer.
The level scale runs from 1 to 4.99. Level 1 is the favorable end of the scale: the outcome-level framework names Level 1 Optimal and Level 4 Critical, so a smaller value sits nearer Optimal and a larger value nearer Critical. The API serves this number in a field named weighted_score; that name describes how the number is computed, and does not mean that a larger number is a more favorable result.
Two numbers describe each result. The integer tier_level is the level label. tier_continuous is the position within the band of that label, and always falls inside it: tier_continuous is at least tier_level and less than tier_level plus one. Labels, counts and prose use tier_level; figure positions and statistics use tier_continuous.
Level 1 is Optimal, Level 2 is Acceptable, Level 3 is At-risk, and Level 4 is Critical. These are definitional category names supplied by the outcome-level framework; what a category means for any reader, community, or decision is not specified by COEQWAL.
A key outcome value is the unweighted mean over the locations in that key outcome. Every location counts equally, regardless of the people, acres, or acre-feet it represents.
Any difference between two values under different hydroclimates contains both a hydroclimate effect and a management effect; the two are separable only through the decomposition, because each is defined against its own reference. A strategy is compared with current operations under the same hydroclimate. Comparing one strategy with itself across hydroclimates is a different quantity: the hydroclimate effect plus the change in the management effect. The hydroclimate effect is always measured on current operations, not on the strategy.
One threshold governs every claim and every count here. A difference smaller than 0.1 on the level scale is not reported as movement, and a location is not counted as differing from its comparison. An outcome level is a summary built so that results in nine key outcomes with no shared unit can be compared, and 0.1 on the level scale is the finest reading it carries; a smaller difference is left unstated rather than described.
The five hydroclimates were chosen to span a range of climate stress levels. They are not a sequence, a trend, or a forecast, they carry no probabilities, and no mean is taken over them.
A run ID identifies one modeling run of one strategy under one hydroclimate. It is an internal identifier, used for citation and for tracing a value back to the data platform, not a name for the strategy; the public identity of a strategy is its descriptive name.
Level values are reported to one decimal place throughout this brief — in the prose, in the figure and in the table. The level scale does not carry meaning finer than that. Each effect shown is the difference between the floored values, except that an effect smaller than 0.1 on the level scale, which is the threshold this brief reports movement at, is shown as 0.0, so a row containing one does not add up. Values are floored rather than rounded, so a printed value stays inside the band its own label names; full-precision values are in the machine-readable sidecar this brief is built from.