Drain Rock Gravel – Premium Virgin Crushed & Screened for Northern California Projects
 
Our Drain Rock Gravel is a high-quality, virgin crushed and screened angular rock, ideal for drainage systems, erosion control, and construction applications throughout Marin, Napa, Sonoma, and Solano counties. Sourced from trusted Northern California quarries, this rock is engineered for durability and optimal water flow. Available in multiple sizes (nominal) — 1/4", 3/8", 1/2", 3/4", 1-1/2", and 3" — it’s the perfect choice for residential, commercial, and municipal projects requiring long-lasting performance.
 
The natural blue/gray tones (color vary by quarry source) offer both functionality and a clean, professional look, making it suitable for visible landscape features as well as below-ground installations. Whether you’re building a French drain in Napa, stabilizing a slope in San Rafael, or backfilling a retaining wall in Petaluma, our Drain Rock Gravel delivers reliability you can count on.
 
Common Applications by Size
1/4" Drain Rock
Best for: Fine drainage layers, root zone aeration, permeable paver joints and small planter boxes where limited space requires precise drainage control.
Commonly used in: Benicia, Yountville, and downtown Napa for garden beds, rooftop planters, and small trench applications needing fine aggregate flow.
 
3/8" Drain Rock
Best for: French drains, residential trench drains, and lightweight drainage layers in planter boxes.
Commonly used in Napa and Sonoma gardens for improving soil drainage and preventing root rot.
 
1/2" Drain Rock
Best for: Perforated pipe backfill, landscape drainage channels, and utility trench bedding.
Popular for small-scale projects in Mill Valley, San Rafael, and other Marin County hillside properties where space is limited.
 
3/4" Drain Rock
Best for: Driveway base layers, retaining wall backfill, and large-scale French drains.
Widely used in Vacaville, Vallejo, and American Canyon for both drainage and light-duty road base applications.
 
1-1/2" Drain Rock
Best for: Heavy-duty drainage fields, slope stabilization, and erosion control along creek banks.
Favored in Petaluma and Santa Rosa for its ability to handle high water flow in stormwater management systems.
 
3" Drain Rock
Best for: Rip-rap slope protection, culvert outlets, and heavy-duty erosion control.
Used by contractors in Fairfield and Novato to stabilize embankments and prevent washouts during rainy seasons.
 
Weight Per Cubic Yard
~1.3  to 1.5 tons
 
Material Specs & Technical Notes
Type: Virgin crushed, screened angular rock.
Available Sizes: 3/8", 1/2", 3/4", 1-1/2", and 3" all nominal.
Color: Predominantly blue/gray; color vary by quarry source in Marin, Napa, Sonoma, and Solano counties.
Source: Sourced from select Northern California quarries to meet strict quality standards.
Gradation: Meets common drainage and backfill gradation ranges (specific sieve analysis available upon request).
Water Permeability: Excellent — allows efficient drainage and prevents standing water.
Compaction: Non-compacting; ideal for maintaining void space in drainage systems.
Durability: High resistance to weathering, abrasion, and water flow, ensuring long-term performance.
Standards: Commonly supplied to meet Caltrans Section 68 (Drain Rock) specifications and ASTM C33 (where applicable).
Packaging: Bulk truckload delivery — minimum order quantities may apply depending on size and location.
 
Delivery Notes
At North Bay Materials, we provide fast, reliable bulk delivery of Drain Rock Gravel across Marin, Napa, Sonoma, and Solano counties. All sizes — from 1/4" to 6" — are available for direct drop-off to residential, commercial, and municipal job sites.
Delivery Method: All drain rock is delivered loose in bulk via dump truck.
Order Minimums:
Smaller sizes (3/8", 1/2", 3/4"): Minimum 3 and maximum 24 tons per order. 
Larger sizes (1-1/2", 3"): Minimum 3 and maximum 24 tons per order, depending on quarry source.
Truck Access Requirements:
Minimum 12 ft wide entry clearance for dump truck access.
Firm, level ground required for safe unloading.
Lead Time: Most deliveries are scheduled within 1–3 business days, with priority given to local contractors.
Multi-Size Orders: Multiple sizes can often be delivered in the same load if sourced from the same quarry.
Special Orders: Larger 3" and 6" rip rap-style drain rock may require extra lead time or quarry direct scheduling.
Whether you need 3/4" drain rock for a French drain in San Rafael or 6" rock for shoreline reinforcement in Bodega Bay, our team ensures you get the right size, on time, and at competitive rates. Get a shipping quote and have it delivered to your site!
 
 
Frequently Asked Questions
Q: Which size drain rock should I use for my project?
A:
1/4" or 3/8": For planter beds, permeable base, small trench drains, utility backfill, and general landscaping.
1/2" or 3/4": For most French drains, driveway base, and retaining wall backfill, and landscaping.
1-1/2": For heavy drainage fields and slope stabilization.
3" & 6": For rip rap erosion control, culvert outlets, construction entrances and shoreline reinforcement.