Rip Rap RSP Rock — Engineered for Erosion Control & Slope Protection

Rip Rap RSP Rock is a heavy, angular stone designed to stabilize slopes, shorelines, and drainage channels against erosion and water flow. Available in sizes ranging from 3–6" to 24"+ boulders, this rock provides exceptional durability and interlocking strength for civil, environmental, and landscape construction projects. North Bay Materials supplies and delivers Rip Rap across Marin, Sonoma, Napa, and Solano counties — ideal for retaining banks, culverts, and coastal defense systems.

9-18" Rip Rap Delivered to a project in Richmond CA (Contra Costa County)

Composition, Engineering Value & Technical Specifications

Rip Rap RSP Rock (also referred to as RSP Rock or Slope Protection Rock) is a dense, angular aggregate engineered to resist displacement under hydraulic stress. Unlike rounded river rock, RSP rock interlocks naturally due to its fractured surfaces, creating a stable armor layer that absorbs and deflects water energy — essential for long-term slope stability and erosion control.

Each stone is produced from high-quality quarried rock, typically granite, basalt, or similar dense materials, and screened to meet Caltrans and ASTM gradation standards for rip rap applications. Its angular geometry provides frictional resistance that prevents rolling or shifting even in steep or high-velocity conditions.

Technical Specifications

Property	Specification
Material Type	Angular quarried rock (granite or basalt)
Gradation Sizes Available	3–6", 6–9", 9–18", 18–24", 24"+ boulders
Typical Density	1.5–1.8 tons per cubic yard
Shape	Angular fractured rock with rough faces for interlock
Color Range	Gray, blue-gray, or tan-brown depending on quarry source
Caltrans Specification Reference	Section 72 – Slope Protection (RSP)
Common Classifications	Light, Facing, or Heavy Rip Rap (RSP ¼ Ton – 6 Ton)
Durability	High — resists freeze/thaw, abrasion, and long-term UV exposure
Permeability	Excellent — allows drainage while protecting soil structure

Engineering Value

Rip Rap RSP Rock is specified by civil engineers and general contractors for:

• Slope stabilization and embankment reinforcement

• Channel lining and culvert outlet protection

• Coastal and streambank erosion control

• Retaining wall backfill protection

• Bridge abutment and drainage basin construction

Its interlocking structure helps dissipate flow energy, prevent soil loss, and maintain structural integrity across both natural and engineered terrains.

12-24" Rip Rap

Common Applications & Installation Guidelines

Rip Rap RSP Rock is one of the most trusted materials for erosion control and slope stabilization across infrastructure, environmental restoration, and landscape development projects. Its combination of angular strength, mass, and permeability makes it an ideal solution wherever soil, water, and gravity interact.

Common Applications

Slope & Embankment Protection

Used along cut slopes, detention basins, and drainage ditches to prevent soil erosion caused by runoff or wave action. Larger rock sizes (9–18", 18–24") are typically specified for steep grades or high-flow conditions.

Shoreline & Streambank Stabilization

Essential in coastal and river engineering, rip rap acts as armor stone, absorbing energy from waves or current while maintaining natural drainage and soil integrity.

Culvert & Pipe Outlet Protection

Placed around culvert ends, storm drain outlets, and spillways to slow water velocity and prevent scour or undercutting at discharge points.

Retention Ponds & Channel Lining

Used to armor channels, swales, and retention pond perimeters to prevent siltation and maintain long-term structural stability.

Bridge Abutments & Infrastructure Support

Installed at the base of bridge abutments, piers, or road embankments to prevent washouts during heavy storm events.

Recommended Size Selection

Application Type	Recommended Rip Rap Size
Drainage Swales & Culverts	3–6" or 6–9"
Slope Protection (2:1 or gentler)	9–18"
Retaining Banks or Road Embankments	18–24"
High-Velocity Channels or Shorelines	24"+ Boulders
Decorative or Landscape Features	3–6"

Installation Guidelines

• Subgrade Preparation: Excavate and compact the subgrade to provide a stable base, ensuring proper slope and grade.

• Geotextile Placement: Use a nonwoven filter fabric beneath the rip rap to prevent soil migration and enhance drainage.

• Rock Placement: Install in a uniform layer; avoid end-dumping which can cause segregation. Stones should interlock tightly to minimize voids.

• Layer Thickness: Typically 1.5× the nominal rock diameter (e.g., 18" stone requires ~27" layer).

• Inspection & Maintenance: Regularly inspect for displacement after storm events and replenish as needed to maintain coverage.

4-9" Rip Rap used for Drainage Application

Delivery, Coverage Rates & Local Availability

At North Bay Materials, we make it simple for contractors and civil engineers to source and receive Rip Rap RSP Rock directly at their job sites—without delays or logistical complications. Our dump-truck fleet is equipped to handle both residential and commercial access points, ensuring accurate placement and dependable service throughout the North Bay region.

Delivery Service

• Truck Types: 10-wheeler, Transfer, End Dump, Super Tag dump trucks (rated for 20-25 ton payloads)

• Delivery Rate: $150/hour round-trip local haul (quoted based on distance)

• Minimum Order: 10 tons (approx. 6–7 cubic yards)

• Maximum per Load: 23–25 tons depending on material density and haul route

• Material Unloading: Driveway, roadside, or designated project drop zone with safe truck access

Delivery is available across: Marin County (San Rafael, Novato, Mill Valley, Tiburon, Corte Madera, Fairfax)Napa County (Napa, Yountville, St. Helena, Calistoga, American Canyon)Sonoma County (Petaluma, Santa Rosa, Healdsburg, Sonoma)Solano County (Benicia, Fairfield, Vacaville, Dixon)

Coverage Rates

Material Size	Weight per Cubic Yard	Approx. Coverage per Ton	Typical Layer Depth
3–6"	~1.5 tons/yd³	40–50 sq ft	8–10 inches
6–9"	~1.6 tons/yd³	25–40 sq ft	10–12 inches
9–18"	~1.7 tons/yd³	15–30 sq ft	12–18 inches
18–24"	~1.7 tons/yd³	10–20 sq ft	18–24 inches
24"+ Boulders	variable	variable	≥ 24 inches

Tip: For heavy-flow zones or shoreline defense, plan for at least 1.5× the nominal stone diameter as your layer thickness for proper interlock and stability.

Local Quarry Sourcing

Our Rip Rap RSP Rock is sourced from select Northern California quarries—ensuring consistent gradation, strength, and regional availability. Depending on location, colors may range from blue-gray granite to tan-brown basalt, helping match both structural and aesthetic project goals.

Cost Efficiency, Environmental Benefits & Why Choose North Bay Materials

Cost Efficiency

Rip Rap RSP Rock offers one of the most cost-effective long-term erosion control solutions in civil and environmental construction. Unlike concrete armoring or retaining wall systems that require high installation and maintenance costs, rip rap provides:

• Low upfront installation cost

• Minimal maintenance requirements

• Natural drainage and filtration benefits

• Long service life, even under continuous hydraulic load

At $55–$85 per ton, it delivers superior performance value across a wide range of municipal, commercial, and private projects. For bulk orders or recurring deliveries, North Bay Materials offers custom quotes based on tonnage and distance, ensuring optimized pricing for every job site.

Environmental & Structural Benefits

Rip Rap RSP Rock not only protects engineered slopes — it supports environmental integrity.

• Reduces soil erosion and sediment runoff into waterways

• Encourages natural vegetation growth between stones, improving ecological stability

• Promotes groundwater infiltration while dissipating surface runoff

• Provides habitat for aquatic and terrestrial species in restoration projects

By allowing water to flow naturally while holding soil in place, rip rap contributes to sustainable water management practices that align with state and local stormwater requirements.

Why Choose North Bay Materials

With over a decade of experience in the landscape and aggregate supply industry, North Bay Materials has become a trusted resource for construction professionals throughout Marin, Sonoma, Napa, and Solano counties. Here’s what sets us apart:

• Proven Material Quality: All rip rap products meet Caltrans Section 72 and ASTM durability standards.

• Local Delivery Expertise: Fast, efficient dump truck service for small and large projects alike.

• Contractor-Friendly Support: Quick quotes, clear communication, and flexible scheduling.

• Regional Knowledge: We understand North Bay terrains, soil types, and hydrological challenges.

Whether you’re armoring a slope, lining a drainage channel, or stabilizing a shoreline, we’ll help you specify and deliver the right size and grade of Rip Rap RSP Rock for lasting results.

Order Rip Rap RSP Rock for Your Next Project

Ready to stabilize your slope, protect your shoreline, or armor your drainage system? North Bay Materials supplies and delivers Rip Rap RSP Rock directly to your jobsite throughout Marin, Napa, Sonoma, and Solano counties. Our local trucking service ensures quick turnaround times, transparent pricing, and consistent product quality.

👉 Order Rip Rap RSP Rock or📞 Call 707-940-9419 to request a project-specific quote today. We’ll help you select the right size and tonnage for your project’s design requirements.

Rip Rap Rock (RSP) (sold per ton)

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Frequently Asked Questions About Rip Rap RSP Rock

Q1. What does “RSP” mean in Rip Rap RSP Rock?

“RSP” stands for Rock Slope Protection. It refers to angular rock used to protect soil embankments, riverbanks, and coastal slopes from erosion due to rainfall, runoff, or water flow.

Q2. How do I know which size of Rip Rap to use?

Size depends on hydraulic velocity and slope grade. For gentle slopes or small channels, 6–9" is typical. For steep slopes or high-flow conditions, 18–24" or larger boulders are recommended.

Q3. What is the difference between Rip Rap and Drain Rock?

Drain rock is smaller, rounded, and primarily used for filtration and bedding. Rip Rap is angular, heavier, and designed to stay in place under hydraulic stress.

Q4. Does North Bay Materials provide installation services?

While we don’t install materials directly, we can refer you to trusted local contractors and provide detailed specifications to ensure proper placement.

Q5. What’s the typical coverage per ton?

Coverage varies by size — smaller rip rap covers 40–50 sq ft per ton, while large boulders may cover only 10–15 sq ft. For accurate estimates, use our Material Calculator.