Excavation in 97390 covers Tidewater and the small handful of properties strung along the Alsea River from the Waldport-end of the estuary upstream to the Five Rivers junction. This is a tiny zip with a specific set of conditions. Most work here is private-property site prep -- vacation-cabin foundations, river-access driveways, septic systems on parcels where city utilities will never reach, and the occasional small-commercial dig for the recreation-anchored businesses along Hwy-34. Cojo dispatches Lincoln County coast jobs from our Hood River yard, scheduling around the summer window when water tables drop and the haul roads firm up. A river-frontage dig in Tidewater is paperwork-heavy because of salmon-stream setback and Oregon DSL rules, and we plan accordingly.
What 97390 Excavation Jobs Actually Look Like
The 97390 footprint is small but the work types are distinct. River-frontage residential is the largest category -- new-build cabin foundations on Alsea River bench lots, retrofit septic systems on parcels older than current code, and access-road rebuilds for the long private driveways that feed the riverside properties. The second category is utility and trench work -- water-line replacements on shallow-table parcels, electrical-trench from new transformers, and propane-tank pads. The third is recreation-business site prep -- boat-launch maintenance, RV-park pad expansion, and the small commercial parcels along Hwy-34 that serve the salmon-fishing and kayaking traffic.
Practical scope on Tidewater work tracks like this. A river-access driveway dig runs 400 to 2,000 cubic yards depending on length, slope, and whether spoils have to be hauled off-parcel. Septic systems run 30 to 100 cubic yards for the typical tank-plus-drainfield install, sized by household and soil percolation rate. Cabin foundation pads are 50 to 200 yards for a typical single-story footprint. We work off a Lincoln County base map, locate utilities through Oregon One-Call, and document hauled-off volume by truck count.
Lincoln County Coast Soil and Salmon-Stream Reality
Tidewater sits on Alsea River alluvial deposits -- a mix of sand, gravel, and silt loam with a high water table that climbs to within 18 inches of the surface during winter. That subgrade is challenging for excavation work in multiple ways. Foundation pads need over-excavation to a competent base layer because the upper soil profile compresses under load. Septic systems are highly site-specific because percolation rates vary widely across short distances. And winter excavation gets bogged in saturated soil that smears under track equipment and turns to soup under truck wheels.
We schedule the deep work in 97390 between June and early October for that reason, with surface grading and rough work running shoulder-season where haul roads allow. The salmon-stream setback rule is the biggest paperwork constraint here. The Alsea River is a documented salmon-bearing stream, which puts work within 100 feet of the bank under Oregon DSL removal-fill jurisdiction and may require ODFW review. Bank stabilization, in-water work, or any cut that delivers sediment to the river requires a permit. We pull that paperwork as part of the bid -- a contractor who tells you it is not necessary is going to get you stop-worked.
Industry Cost Picture for a 97390 Excavation Job
Cost in 97390 is driven by haul distance from Cojo's nearest equipment yard, the salmon-stream setback paperwork, water-table timing, and whether spoils can stay on-parcel or have to be hauled off.
Industry Baseline Range
| Project Type | Cost Per Cubic Yard | Typical Total |
|---|---|---|
| River-access driveway prep | $12 to $25 | $5,000 to $25,000+ |
| Septic system, tank and drainfield | $15 to $40 | $9,000 to $30,000+ |
| Cabin foundation pad | $14 to $30 | $4,000 to $12,000 |
| Utility trench, 100 to 500 ft | $18 to $50 | $4,000 to $25,000 |
| Setback bank stabilization | $25 to $80 | $8,000 to $50,000+ |
Current Market Reality
Tidewater pricing runs above valley pricing because of the equipment-mob distance from any Cojo yard, the limited number of contractors who pull salmon-stream permits, and the steep access on most river-bench parcels. Spoils hauling adds real cost when the parcel cannot accommodate fill on-site. A river-access driveway the baseline frames at $14 a yard is more likely $18 to $24 here today. Septic systems in saturated soil profiles commonly run 50 percent over baseline because of the soil-evaluation cycle and drainfield sizing requirements. We do not quote excavation over the phone -- a real number requires a site walk and a soil test for septic work. For broader Lincoln County context, see our excavation in Lincoln County guide.
Permits, Alsea Setback, and the DSL Process
Lincoln County Public Works runs unincorporated 97390 permits, with septic systems going through Lincoln County Environmental Health for soil evaluation and design review. Cabin or single-family-dwelling permits run through county planning. The Alsea River setback piece is where Tidewater work gets paperwork-heavy. Any removal-fill within 100 feet of the ordinary high-water line requires either a DSL general authorization or an individual removal-fill permit, and the more sensitive the work, the more documentation. We file the DSL paperwork on every river-frontage job and coordinate with ODFW for any work that involves in-water timing windows.
DEQ 1200-C stormwater permitting kicks in once you disturb one acre. That threshold is rarely hit on a single-family cabin job but does come up on the recreation-business work along Hwy-34 and on the larger RV-park pad expansions. We handle that filing. Oregon One-Call locates run 48 hours before any dig, and we work with the Tidewater-area water-line operators to confirm shallow-utility locations before we cut.
How To Hire For This Zip
Ask three things of any 97390 bidder. First: who is pulling the salmon-stream permit, and is the DSL filing cost in the bid? Second: when does your crew plan to dig, and what is the contingency if water-table conditions push the schedule? Third: where are spoils going, and what is the hauling cost added per yard? A contractor who has not pulled an Alsea River setback permit before is going to learn on your dime.
Cojo runs Tidewater work alongside our nearby Gleneden Beach asphalt paving crews and our concrete curbing in Siletz routes, so a property that needs site prep plus driveway paving plus drainage curb goes through one company. Equipment list and project-type detail is on our excavation services page.
Ready to price a 97390 site-prep, septic, or cabin foundation job? Schedule a free site visit and we will walk the property, confirm setbacks, run the soil context, and give you a written quote that holds up against real Alsea River conditions. No phone-quote shortcuts.