NEW ROOTS DEVELOPMENT
Home›Tool Guide›VDC Survey›Adjoiners + GIS

Generate Wetland Areas

Generates wetland areas two ways: pulls every National Wetlands Inventory polygon in a picked window from the live USFWS service (planning-level limits, already in the drawing's State Plane grid), or connects the delineator's surveyed flag points into closed boundaries. Closed polylines + hatch + labels + a summary table + CSV. Runs in plain AutoCAD as well as Civil 3D.

Command VDCWETLAND VDCWETLANDS · VDC Survey tab › Adjoiners + GIS panel
Generates wetland areas two ways: pulls every National Wetlands Inventory polygon in a picked window from the live USFWS service (planning-level limits, already in the drawing's State Plane grid), or connects the delineator's surveyed flag points into closed boundaries. Closed polylines + hatch + labels + a summary table + CSV. Runs in plain AutoCAD as well as Civil 3D.
VDCWETLAND, NWI polygons from the live USFWS pull, or the surveyed flags connected in order query window (picked) PFO1A FRESHWATER FORESTED/SHRUB 1.23 AC ± WL-A1 WL-A2 WL-A3 WETLAND A 0.42 AC ± WETLAND AREAS SUMMARY DRAFT, NWI is planning-level screening data, not a jurisdictional delineation. AREA SOURCE NWI CODE TYPE AC (DRAWN) AC (NWI) 1 USFWS NWI PFO1A FORESTED/SHRUB 1.23 2.50 2 USFWS NWI L1UBHx LAKE 0.87 0.90 3 FIELD FLAGS A FIELD-DELINEATED 0.42 , CSV report beside the drawing carries the same rows + provenance headers. Screening data in, real boundary when it exists NWI pull: window (default) or extents; any State Plane zone; pages past the 1,000-polygon cap and WARNS if still truncated. Flags: WL-A1 / WL-A2 ... group by letter, connect in flag order, one closed boundary per wetland; or pick the points on screen. Re-runs replace each area in place (NWI id / flag letter); Clear removes everything. Labels: code / type / drawn acreage. Not a delineation, field delineation + USACE/state concurrence govern.

What it does

  • Run, NWI pull: every USFWS National Wetlands Inventory polygon intersecting the picked window (or the drawing extents), returned already reprojected into the drawing's State Plane WKID (any NAD83 State Plane zone). Each area: closed polylines per ring (islands too), optional hatch (islands excluded as holes; unknown pattern skips with a note), and a label at a guaranteed-interior point, NWI code, plain-English type, and acreage computed from the drawn limits, each toggleable.
  • Connect flags: the delineator's surveyed flags become the boundary, COGO points matching a description pattern (WL*) group by the letter after the prefix and connect in flag order (sequence numbers, falling back to point number), one closed boundary per letter; or pick the points on screen in order (any host). Labels read WETLAND A, (FIELD-DELINEATED), 0.42 AC ±.
  • Replace-in-place: every entity is stamped with its NWI GLOBALID / flag letter, a re-run replaces that area cleanly, and the funnel prints pages / features / usable / skipped even when nothing comes back.
  • Summary table + CSV: area #, source, NWI code, type, drawn acres, and NWI's published whole-polygon acres side by side; the table keeps its user-dragged position across re-runs.

Modes, seats & caveats

  • Run / Connect flags / Clear, Clear removes every polyline, hatch, label, and table the tool ever drew.
  • Plain AutoCAD: the only Civil 3D API use is the COGO reader, runtime-gated on the host, the NWI pull and pick-points modes fully work on vanilla seats; ships in VDC.Acad.bundle.
  • NWI is a screening product: compiled from aerial imagery at inventory scale, boundaries generalized, small/forested/recent wetlands routinely missing, mapped areas can be upland. Absence of NWI polygons never clears a site. Field delineation and USACE / state concurrence establish the limits; every output path says so.
  • Flag order is boundary order, a self-crossing loop means out-of-order flags; renumber or use pick mode. With WLF-1..n flags, use WLF* (with WL* the F reads as a boundary letter).
  • Network required for the NWI pull; flag modes work offline. Settings at %APPDATA%\VDC\Wetlands\settings.json (env VDC_WETLANDS_SETTINGS).

Dialog

Generate Wetland Areas dialog
Generate Wetland Areas, VDCWETLAND

When to use it

  • Due diligence / concept: showing NWI-mapped wetlands on a site before the delineation exists.
  • After the delineation: connecting the surveyed flag points into the closed, labeled wetland boundary.
  • Permitting exhibits: a hatched, labeled wetland figure with acreage and a summary table in minutes.

How to run it

  1. Run VDCWETLAND - pick the mode (Run / Connect flags / Clear) and the options; click OK.
  2. Run mode: pick the two window corners (or nothing for Extents). The tool queries USFWS, prints the funnel (features returned / usable / skipped), and draws.
  3. Connect flags: matched COGO flags group and connect automatically; in pick mode, click the flags in order and press Enter to close the loop.
  4. Pick the summary table's corner when prompted (Enter skips it). Review the end-of-run summary.
  5. Re-run any time - each area is replaced in place by its NWI id / flag letter. Clear removes everything the tool drew.

Options

  • Coordinate system (WKID): the drawing's State Plane zone - every NAD83 zone is in the list (262), 2273 SC intl ft, 102733 SC US ft, 2264 NC US ft among them; type any WKID for other zones.
  • Area to query: Window (pick two corners - the default) or the drawing extents. A whole-quad pull is never what a site drawing wants.
  • Flag source: COGO points matching a description pattern (Civil 3D hosts), or points picked on screen in order (works everywhere, including plain AutoCAD).
  • Description pattern: wildcard match on the flag descriptions (WL* default; * = any run, ? = one character). Flags group by the letter after the prefix - WL-A1/WL-A2 vs WL-B1 - one boundary per letter, connected in flag-sequence order.
  • Label content: NWI code (PFO1A), plain-English wetland type, and computed acreage (1.23 AC +/-) are each toggleable.
  • Hatch: pattern (GRASS default), scale, and transparency; islands hatch as holes. An unknown pattern skips the hatch with a note - the linework still lands.
  • Wetland layer / text height / style: where everything lands (default C-WETL, auto-created) and how the labels render.

Watch out for

  • NWI is a screening product, NOT a delineation - never let a plan imply otherwise. The drawn limits are planning-grade until a field delineation replaces them.
  • Nothing mapped is not nothing there: small, forested, or recently formed wetlands are routinely absent from the NWI. Absence of NWI polygons never clears a site.
  • Flag boundaries connect in flag order. A self-crossing boundary means out-of-order flags - renumber them or use pick mode.
  • The pattern's prefix matters for grouping: with flags staked WLF-1..n, use WLF* (with WL* the F reads as a boundary letter).
  • Network required for the NWI pull - an outage shows a short message and nothing is drawn from stale data. Flag modes work offline.

Related: Flood QC · FIRM Note · Buffer Yard · Tree Table