The Cach Park area of Tigard is the newer single-family residential pocket adjacent to Cach Nature Park, a City-of-Tigard greenway along the headwaters of Cach Creek. The neighborhood is dominated by post-2000 subdivisions on lots that back up to the greenway or sit within a block or two of it. Driveway installation here is a mix of first-cycle replacement on builder-handoff drives that have run 15 to 25 years, new-construction work on the remaining infill parcels, and ADU additions on parcels where the homeowner is expanding capacity. The greenway adjacency and the City of Tigard stormwater management rules for parcels near the riparian corridor change the install scope in ways that flat-lot subdivision drives elsewhere do not face.
Why Cach Park Installs Have a Greenway Premium
Cach Park parcels are subject to City of Tigard riparian buffer and stormwater management rules that flow from the City's adoption of the Clean Water Services framework. Driveway installations on parcels within the buffer zone (or that drain toward the buffer) cannot discharge stormwater directly to the greenway -- the design has to incorporate infiltration, treatment, or both. Most Cach Park installs include a swale, an infiltration trench, or a rain garden component as part of the scope. The base course typically runs thicker than a higher-elevation lot to handle the saturated-subgrade conditions that show up after wet-season runoff.
The Tigard driveway excavation page covers the dirt-work and drainage scope that anchors most Cach Park installs. The drainage component is rarely a small line item.
The Three Cach Park Install Patterns
Most Cach Park install demand falls into three patterns. First, builder-handoff redesigns on post-2000 drives that have reached the end of the original builder-spec service life and the homeowner wants a wider, longer, or differently-shaped drive rather than a like-for-like replacement. Second, new-construction installs on the remaining infill parcels, where the City stormwater management plan and the parcel-specific civil drawings dictate the drainage approach from the schematic-design phase. Third, ADU additions on parcels where the homeowner is adding a separate living unit and the existing drive cannot serve both the main house and the ADU access requirement.
The mature canopy in the older portions of the neighborhood -- western red cedar, bigleaf maple, and Oregon ash near the greenway -- means root mitigation appears on most install bids. Root barrier scope is the standard answer where the new drive's edge runs within 6 to 10 feet of a mature tree.
Industry Cost Picture for Cach Park Installation
The ranges below cover realistic Cach Park install scope. Drives with substantial stormwater treatment scope or greenway-buffer compliance work land in the upper third.
Industry Baseline Range
| Scope | Cost Per Sq Ft | Typical Total |
|---|---|---|
| Standard single-car install | $8 to $13 | $4,500 to $8,500 |
| Two-car install with drainage | $9 to $15 | $7,500 to $16,000+ |
| Builder-handoff redesign (wider or longer) | $9 to $14 | $9,000 to $25,000+ |
| ADU access install | $9 to $14 | $7,000 to $20,000+ |
| Stormwater treatment feature | $1,800 to $6,500+ | Per feature, varies by spec |
| Right-of-way driveway approach | $1,800 to $5,000+ | City permit, sidewalk tie-in |
Current Market Reality
Cach Park install bids regularly land above the flat-lot baseline for three reasons. First, the greenway-adjacent stormwater rules require infiltration or treatment scope on most parcels, and that scope adds dollars and schedule. Second, the base course typically runs thicker than a higher-elevation lot to handle the saturated subgrade after Pacific Northwest wet seasons, which adds aggregate import and recompaction line items. Third, the City of Tigard right-of-way approach permits and ADA accessible-route reviews at the sidewalk tie-in add a small permit fee and a 2-to-4-week timeline. The asphalt paving cost in Tigard page covers the broader citywide pricing reference, and the driveway installation cost in Wilsonville page covers a parallel south-side reference for similar greenway-adjacent installs along the Willamette.
Permits, Greenway Buffer, and the Approach
The permit footprint for a Cach Park install depends on three things. First, whether the parcel sits inside the City of Tigard riparian buffer overlay or drains to it, which requires the stormwater treatment scope and a written buffer-compliance note in the bid package. Second, whether the drive ties into a city right-of-way -- almost always yes on the subdivision streets -- which triggers a City of Tigard driveway-approach permit with sidewalk and accessible-route review. Third, whether the drive is widening or relocating compared to the original builder spec, which can trigger a separate site-development review. Cojo runs the permit submittal in parallel with the bid so the homeowner is not stuck in a 4-to-8-week paperwork hold.
How to Vet a Cach Park Install Bidder
Three questions filter the bidder list. First, ask whether the bid includes stormwater treatment scope and a buffer-compliance note if the parcel is in or adjacent to the riparian overlay. A bidder who skips the greenway-buffer compliance is shifting risk you should not accept. Second, ask whether the base-course aggregate depth in the spec is sized for saturated-subgrade conditions, or whether it is a flat-lot template. Third, ask how the bidder is handling root mitigation near the mature canopy. A bidder who hedges on any of those is the wrong fit.
Sealcoat Follow-Up and Maintenance
Once a new drive is down, the first sealcoat at 18 to 24 months protects the surface against canopy debris and freeze-thaw cycles. The Cach Park sealcoating page covers the rotation scope.
The newer-build character of most Cach Park drives means the maintenance cycle can run on a 30-to-36-month rotation rather than the tighter 24-month cycle that older neighborhoods need. The drives are starting at year zero rather than year forty, the asphalt is structurally sound, and the sealer is doing preventive maintenance on a good surface rather than papering over an aging one. A homeowner who locks the new drive into a calendar-controlled rotation program from year one can reasonably expect 30 to 40 years of service before any structural repair, versus 20 to 25 years on a drive that skips the rotation.
Cojo runs ongoing maintenance and drainage rework through our excavation services line. Ready to get the install priced? Schedule a site walk and Cojo will measure the drive, scope the drainage and the buffer compliance, and write a number that reflects the actual greenway-adjacent conditions.