Gravel, Rock, Sand and Soil Delivery in Chico, CA

Vina sandy loam over river-laid alluvium

The USDA soil survey maps Vina fine sandy loam, sandy substratum, 0 to 2 percent slopes, MLRA 17 at the ZIP's center point, and the Vina series makes up 85 percent of that map unit. Fine sandy loam on top over a sandy substratum is about as easy as building ground gets: loose enough to dig with a shovel, firm enough to compact, and open enough that water does not linger.^[1]

Below the soil, the state geologic map shows Quaternary alluvium and marine deposits, made up of coarse alluvium and fine alluvium. Alluvium is sediment that moving water laid down, in beds of gravel, sand and silt. That layered origin explains the sandy substratum the survey lists under the Vina soil, and it means a deep hole may pass from loam into cleaner sand or even rounded gravel.^[2]

The survey puts the Vina soil in hydrologic group A, so water soaks in fast with little runoff, and it rates the soil well drained. Shrink-swell is low, at 1.6 percent. A compacted gravel base laid on this ground will not be lifted by swelling clay, and rain will pass down through it rather than sit beneath it.^[1]

Rain and freeze at the Chico farm station

Weather normals come from the NOAA station at Chico Univ Farm, CA, about 4 miles from the ZIP. It averages 27.4 inches of precipitation a year. Most of that arrives in storms, and on fast-draining Vina ground it sinks in quickly, so a surface that looks soaked in the morning can be dry by afternoon.^[3]

The Chico Univ Farm station counts 40 days a year when the low falls to 32 F or colder. Those are mostly light frosts on clear nights, enough to matter for tender plants but rarely enough to lift a well-drained gravel base.^[3]

The station's median last spring freeze is March 4, and its median first fall freeze is November 17. Warm-season beds go in safely after the March date, and frost cloth or a fresh layer of mulch is worth having ready as the November date nears.^[3]

During a steady rain, walk the yard and note where water gathers near the house or the drive. On group A ground those spots tend to be dips in the grading, not soil that refuses to drain, so a little added Topsoil or a short trench of Drain Rock tends to clear them for good.^[1],[3]

Building a gravel drive on sandy ground

On Vina sandy loam the work starts with compaction, not drainage. Scrape away the organic top few inches, wet the sandy loam lightly and run a plate compactor over it until it stops settling. Because the soil drains well and holds little clay, fabric is a choice rather than a must, though it helps keep the base clean where trucks turn or park.^[1]

Spread Road Base in two or three lifts, wetting and compacting each one until it is hard. The low 1.6 percent shrink-swell rating means the finished base holds its grade through wet and dry seasons with little movement. For the surface, 3/4" Crushed Stone or Driveway Gravel gives good traction, and #57 Crushed Stone is a cleaner option for a drive where you want rain to vanish straight through.^[1]

The ground at the survey point stands 210 feet above sea level. The Vina map unit is nearly level, at 0 to 2 percent slopes, so set a slight crown in the drive by hand and give the low edge a strip of Drain Rock or River Rock to catch what runs off.^[1],[4]

Beds, orchards and backyard gardens

Fine sandy loam warms fast in spring and drains fast after a storm, which plants like, but it also loses water and nutrients quickly. Work Compost into each bed every year, and blend Topsoil with Compost to fill low spots or build new beds. Garden Soil is a ready-mixed option for raised beds and vegetable boxes.^[1]

Mulch is the second half of the plan. Brown Shredded Mulch, Black Shredded Mulch or Red Mulch spread a few inches deep keeps the sandy loam from drying out between storms and evens out soil temperature on cold nights. Wood Chips suit the ground under fruit trees and the paths between rows, where they break down slowly and feed the soil.^[3]

For paths through a garden, Walkway Gravel or Decomposed Granite packs into a firm surface that sheds little dust. Pea Gravel stays loose and drains well, so it suits play areas and the space around a fire pit.^[1]

#57 Crushed Stone against Decomposed Granite

Two surfaces cover most backyard projects on Vina ground: open, clean #57 Crushed Stone and tight-packing Decomposed Granite. They behave almost opposite ways. #57 Crushed Stone has no fines, so water drops straight through it into the group A sandy loam below. Decomposed Granite is full of fines that bind into a crust once wetted and rolled, so it sheds a light rain across its surface and only drinks a heavy one at its edges.^[1]

With 27.4 inches of yearly precipitation at the Chico Univ Farm station, both surfaces stay usable through the wet months on this well-drained soil. #57 Crushed Stone makes the better choice for a parking spot, a gravel strip beside the garage or a base under a hot tub pad, where water must never sit. Decomposed Granite is the better pick for a patio floor or a path you walk in slippers, where a smooth, firm surface counts for more than drainage.^[1],[3]

On low shrink-swell ground, both stay level for years once edged. If you want something in between, Walkway Gravel packs firmer than #57 Crushed Stone but drains better than Decomposed Granite, and it suits a garden path that carries both feet and a wheelbarrow.^[1]

Homes in ZIP 95926 and the Caltrans base spec

The Census counts 18,549 housing units in ZIP 95926. Detached single-family houses account for 50 percent of them, and owners live in 40 percent of the occupied homes.^[5]

Chico as a whole has 46,625 housing units, with the same 50 percent share of detached houses. The median build year is 1977 in the ZIP and 1983 across the city. With a mix of houses and rentals, orders here run from a few yards of mulch for a rental bed to a full truck of base for a new driveway.^[5]

For state highway work, Caltrans calls for Class 2 Aggregate Base under Section 26-1.02B of its Standard Specifications (2026). That standard describes the compacted, well-graded stone course laid beneath its pavements.^[6]