Drought-Year Wetland Delineation Under Deadline Pressure
A GIS analyst on a consulting team is supporting a Clean Water Act Section 404 permit for a 46 acre warehouse site. The National Wetlands Inventory maps 3.1 acres of palustrine emergent wetland on the parcel. A field delineation was done in mid-August of a drought year; the team flagged 0.8 acres, and 2 of 5 soil pits showed hydric indicators. The previous consultant's 2010 delineation found 2.4 acres, which was never submitted and never verified by the Corps. The client's project manager emails: 'Just submit the NWI layer with the 0.8 acre line, or better, send the map with no wetlands so we can get in the queue before the 10 day deadline. We can fix it later. Nobody checks the GIS metadata.' The firm's principal says the permit application is the client's document and asks the analyst to 'keep it clean.' The analyst's name will appear as the map author and the firm's seal is on the application.
1. What should the analyst do, and what obligations govern the decision?
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This is a request to misrepresent a known condition on a federal permit application, not a styling preference. Removing the NWI layer, or submitting a 'no wetlands' map after the firm has documented hydric indicators, is a material omission. It exposes the client and the firm to enforcement and false-statement exposure, and it puts the analyst's name and the firm's seal on the product.
Refuse the specific edits in writing and escalate to the principal with the technical record attached. Then offer the compliant path: submit the 0.8 acre delineation as the firm's field determination, disclose the drought conditions and the two hydric indicators, keep NWI on the map as a reference layer labeled with its source and its non-jurisdictional status, and request a preliminary jurisdictional determination from the Corps.
The 10 day deadline is not actually in conflict with doing this correctly. A preliminary jurisdictional determination request or a complete delineation report with a documented data gap does not require a second field season. Deleting a layer, backdating a product, or editing metadata to make the question go away does.
2. How would you technically resolve the 0.8 acre, 2.4 acre, and 3.1 acre discrepancy?
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The three numbers may conflict less than they appear. NWI is a landscape-scale remote-sensing product and was never a delineation, so 3.1 acres is a hypothesis. The 2010 figure may reflect a wetter period or a different regional supplement. The August drought figure is plausibly an undercount.
The 1987 Corps manual requires three parameters: hydrophytic vegetation, hydric soils, and wetland hydrology. Two of five pits showing hydric indicators is not decisive in either direction, so increase plot density and sample along the apparent boundary rather than only inside it.
Hydrology is the parameter most likely to be missing in a drought, and it can be supported with off-site evidence: precipitation departure over the preceding 3, 6, and 12 months, nearby stream gage records, a reference wetland on the same soil map unit, and monitoring wells if the schedule permits. Pull historical imagery and LiDAR microtopography while planning a wet-season revisit.
What you must not do is resolve a drought-year delineation by selecting whichever number the client prefers.
3. What limitations belong in the report, and how do you handle the client's instruction to omit the wetlands?
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Document the limitation rather than hiding it: date and duration of the field visit, precipitation departure, which hydrology indicators were and were not observed, plot locations, the soil series and hydric indicator for each pit, and an explicit statement that the delineation was performed under drought conditions and may under-represent wetland extent. Attach the field data sheets.
State clearly that a delineation is a technical recommendation and that the Corps makes the jurisdictional determination. That framing is accurate, and it is also the honest boundary between the analyst's role and the regulator's.
In the client letter, separate three issues: the technical finding (0.8 acres, low confidence under drought), the regulatory process (a preliminary jurisdictional determination request preserves the schedule), and the firm's position (no map will be submitted that omits known wetland indicators).
Keep the email chain and meeting notes. If the firm overrides the analyst and submits the stripped map anyway, the analyst should not be listed as author and should document the reason in writing.