## Facts

- The United States held reservation tidelands at Sandy Point, Washington, in trust for the Lummi Nation; the reservation boundary extended to the low-water mark.
- Waterfront homeowners owned adjacent upland/littoral parcels and constructed shoreline defense structures (e.g., bulkheads and rock revetments) to address erosion.
- Some homeowners previously leased adjacent tidelands from the Lummi Nation but allowed the leases to expire.
- The upland–tideland boundary was ambulatory, moving with natural shoreline change; erosion shifted the boundary landward.
- As the boundary moved, portions of the homeowners’ shoreline structures came to lie on, or intrude into, trust tidelands.
- The United States and the Lummi Nation alleged (1) common law trespass to trust tidelands, (2) unpermitted structures/obstructions in navigable waters under § 10 of the Rivers and Harbors Act (RHA), and (3) as to the Nicholsons, an unpermitted discharge of fill material under the Clean Water Act (CWA).
- The district court found trespass and RHA violations as to the homeowners, found a CWA violation only as to the Nicholsons, ordered removal of certain structures, imposed a $1,500 civil penalty, and denied attorney’s fees under the Equal Access to Justice Act (EAJA).

## Issues

1. Whether shoreline defense structures that become seaward of an ambulatory tideland boundary due to natural erosion constitute a continuing trespass on tribal trust tidelands.
2. Whether maintaining unpermitted shoreline structures within tidal navigable waters violates § 10 of the RHA.
3. Whether the government proved that the Nicholsons discharged fill material below the actual high tide line without a permit, in violation of the CWA.
4. Whether the homeowners were entitled to attorney’s fees under the EAJA, or whether the government’s position was substantially justified.

## Decision

- Affirmed trespass liability where natural shoreline change caused previously lawful upland structures to encroach onto trust tidelands.
- Affirmed RHA liability, holding that continued maintenance of unpermitted structures in navigable waters constituted an ongoing § 10 violation.
- Reversed the CWA judgment against the Nicholsons because the government failed to prove an essential element: that fill was discharged below the high tide line as it actually existed during the relevant period.
- Largely affirmed injunctive relief requiring removal of encroaching/unauthorized structures and affirmed the civil penalty insofar as tied to affirmed violations.
- Affirmed denial of EAJA fees because the government’s overall position was substantially justified despite losing on the CWA claim.

## Legal Principles

- Coastal boundaries between uplands and tidelands generally are ambulatory and move with natural shoreline changes; private shoreline armoring does not unilaterally fix the property line against a sovereign/tribal trust owner.
- A structure that becomes located on another’s land due to an ambulatory boundary can constitute a continuing trespass, supporting injunctive relief including removal.
- Section 10 of the RHA prohibits unauthorized structures or obstructions in navigable waters; ongoing maintenance of an unpermitted structure within tidal navigable waters may be treated as a continuing violation.
- CWA liability for unpermitted discharge of fill requires proof of discharge into waters of the United States at the relevant tidal boundary as it actually existed, not a hypothetical boundary assumed “but for” shoreline structures.
- Under the EAJA, a party is not entitled to fees if the government’s overall position was substantially justified, even if the government fails on a discrete claim.

## Conclusion

The Ninth Circuit held that shoreline defenses that came to encroach on Lummi trust tidelands due to an ambulatory shoreline boundary supported trespass and RHA liability and removal-based relief, but it reversed the Nicholsons’ CWA liability because the government did not prove a discharge below the actual high tide line, and it denied EAJA fees because the government’s litigation position was substantially justified.


United States v. Milner, 583 F.3d 1174 (9th Cir. 2009)