Conservation Alliance of St. Lucie County, Inc. v. U.S. Department of Transportation, 847 F.3d 1309

Background

Port St. Lucie planned a third bridge over the North Fork St. Lucie River to meet growing traffic and evacuation needs; all feasible alignments would affect federally protected § 4(f) lands (an Aquatic Preserve (AP) and Savannas Preserve State Park (SPSP)).
The City, FHWA, FDOT, and multiple state and federal agencies evaluated alternatives in an EIS process; six build alternatives were considered within a selected corridor.
Plaintiffs (Conservation Alliance and Indian Riverkeeper) challenged FHWA’s selection of Alternative 1C, arguing FHWA should have chosen Alternative 6A built with spliced‑beam construction, which would avoid § 4(f) use.
FHWA determined spliced‑beam construction would greatly increase impacts to adjacent non‑§ 4(f) wetlands and that Alternative 6A would cause severe social/community harms (residential/commercial relocations, neighborhood bisecting, noise/visual impacts, potential disparate impact on minority households), so 6A (and 6A Spliced) were imprudent.
FHWA selected Alternative 1C as the least‑harm alternative, adopting mitigation measures including reducing bridge width, water‑quality projects, trail relocations/improvements, and adding ~108.55 acres to SPSP; district court granted summary judgment to FHWA; plaintiffs appealed.

Issues

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether FHWA properly found no feasible and prudent § 4(f) avoidance alternative	FHWA abused discretion by rejecting Alternative 6A Spliced, which would avoid § 4(f) lands	FHWA reasonably found 6A Spliced imprudent because spliced beams would multiply wetland impacts and 6A’s route causes severe social impacts	FHWA did not act arbitrarily; no feasible/prudent avoidance alternative existed
Whether spliced‑beam construction was a feasible/prudent mitigation/avoidance measure	Spliced‑beam would avoid § 4(f) use and thus should have been adopted	Spliced‑beam would require much larger wetland footings, causing far greater non‑§4(f) environmental harm and state agencies preferred piers in AP	FHWA reasonably rejected spliced‑beam as imprudent due to disproportionate wetland impacts
Whether Alternative 6A’s route was imprudent due to social/community impacts	Plaintiffs argued cost/disruption wouldn’t reach §4(f)/Overton Park ‘‘extraordinary’’ threshold to disqualify 6A	FHWA found cumulative social harms (relocations, bisected neighborhoods, noise/visual impacts, higher % minority relocations) sufficient to render 6A imprudent	FHWA’s prudence determination upheld as reasonable (cumulative social harms made 6A imprudent)
Whether FHWA satisfied § 4(f)(2) "all possible planning" and least‑harm analysis when selecting 1C	Plaintiffs argued FHWA should have prioritized avoidance of §4(f) lands and that mitigation/analysis was inadequate	FHWA performed a least‑harm balancing across regulatory factors, coordinated with jurisdictional agencies (FDEP, SFWMD, etc.), and crafted mitigation adding >108 acres and other benefits	FHWA’s least‑harm and mitigation planning were thorough and not arbitrary or capricious; selection of 1C affirmed

Key Cases Cited

Citizens for Smart Growth v. Sec’y of Dep’t of Transp., 669 F.3d 1203 (11th Cir.) (framework for §4(f) review: scope, arbitrariness, procedures)
Citizens to Preserve Overton Park, Inc. v. Volpe, 401 U.S. 402 (U.S. 1971) (§4(f) creates stringent protection for parkland; judicial review standard)
Druid Hills Civic Ass’n, Inc. v. Fed. Highway Admin., 772 F.2d 700 (11th Cir.) (least‑harm balancing under §4(f))
Sierra Club v. Van Antwerp, 526 F.3d 1353 (11th Cir.) (deferential APA review of agency NEPA/§4(f) decisions)
Black Warrior Riverkeeper, Inc. v. U.S. Army Corps of Eng’rs, 833 F.3d 1274 (11th Cir.) (limits of judicial inquiry into agency record)
Safeguarding the Historic Hanscom Area’s Irreplaceable Resources, Inc. v. Fed. Aviation Admin., 651 F.3d 202 (1st Cir.) (Overton Park’s language as gloss on prudence, not replacement of statutory test)