Gravel, Stone and Soil Delivery in Georgetown, TX

Clay that swells, chalk that stops the shovel

The USDA soil survey maps Austin silty clay, 1 to 3 percent slopes, at the ZIP's center point. The Austin series makes up 90 percent of that map unit, so the label describes the ground at that spot with little mixing. The top mineral layer is silty clay. The survey calls it well drained, a rating that describes how deep water stands in the profile, though rain still moves into this clay slowly.^[1]

Two ratings matter most for a builder. The soil sits in hydrologic group D, which means very slow infiltration and high runoff. Its shrink-swell in the top meter is moderate, at 5.1 percent. Clay like this grows when it soaks up water and shrinks as it dries, so a slab or a thin gravel layer laid right on it can crack or rut as the seasons turn.^[1]

The survey also places a restrictive layer, paralithic bedrock, at about 29 inches. Paralithic rock is soft enough to dig with effort but hard enough to slow roots and stop water. Beneath it, the geologic map shows the Austin Chalk, a Late Cretaceous unit of marlstone, chalk and claystone. A post hole on ground like this can hit pale, crumbly rock long before the planned depth.^[1],[2]

Weather at the Georgetown Lake station

The NOAA normals station at Georgetown Lake, TX, about 8 miles away, averages 37.1 inches of precipitation a year and 0.0 inches of snow. Rain tends to come in bursts here, and silty clay in group D sends much of a hard storm off as runoff. Gravel surfaces get scoured at low spots and along edges where that water gathers.^[3]

Cold is brief. The station counts 28 days a year with a low at 32 F or colder. Its median last spring freeze is March 6, and its median first fall freeze is November 24. Planting and seeding go well after the March date, and the long warm stretch means mulch breaks down faster and needs a fresh layer more often than in cooler places.^[3]

A driveway built for moving clay

On clay that swells, the goal is to separate the drive from the soil and keep water out of the subgrade. Strip the topsoil, shape the subgrade with a crown, and roll it firm. Lay a woven geotextile fabric next. It keeps clay from squeezing up into the stone when the ground is wet, and it spreads the load of a truck over a wider area.^[1]

Spread Road Base over the fabric in thin lifts, wetting and compacting each one. A thicker base helps on clay, since a deeper layer bridges soft spots and evens out the swell beneath. Crushed Concrete makes a strong base as well. For the surface, 3/4" Crushed Stone or Driveway Gravel locks into the base, and Asphalt Millings pack into a dark, firm top that sheds water well.^[1]

Where the paralithic layer sits near 29 inches, a deep cut may reach rock. That firm layer can make a good floor for the base, but it will not let water through, so water held above it needs a way out. A trench of #57 Crushed Stone or Drain Rock along the low edge of the drive gives it one.^[1]

Stone for runoff on heavy ground

With high runoff from group D clay, much of the work in a yard here is moving water. A dry creek lined with River Rock carries storm flow across a lawn and looks neat when empty. Riprap holds the outlet of a downspout or a swale where flow is fast. #4 Crushed Stone and 1-1/2" Crushed Gravel fill a deeper French drain trench and keep space for water between their large pieces.^[1],[3]

Choosing between Drain Rock and #57 Crushed Stone for that trench is mostly a matter of finish. Drain Rock is washed and often rounder, so it moves water well and looks clean at the surface. #57 Crushed Stone is angular and packs a bit tighter, so it suits a trench under a path or a drive edge where someone will walk or drive across it.^[1]

Beds on clay with chalk below

Silty clay holds water and nutrients, but it packs hard and drains slowly. A raised bed filled with Garden Soil skips most of that problem. For in-ground beds, work Compost into the top layer, and add Topsoil to raise the planting level above the clay. Brown Shredded Mulch or Wood Chips on top keeps the surface from baking and cracking in summer.^[1]

Decomposed Granite makes a firm path between beds that drains across its surface. Stone Dust Screenings serve as a setting bed under flagstone or pavers, and Concrete Sand works for the joints or as a leveling layer. Red Mulch and Black Shredded Mulch add color near a porch or a fence line.^[1]

Patios, play areas and side yards

A patio on swelling clay needs the same care as a drive, just on a smaller scale. Dig past the dark topsoil, lay fabric, and compact a layer of Road Base before any finish goes down. A slight fall away from the house keeps rain from running toward the foundation, which matters on clay in group D where water does not soak in fast.^[1]

Side yards are often the wettest, shadiest strip on a lot. 3/8" Crushed Stone or #89 Crushed Stone makes a neat, easy walking surface there, and a buried trench of Drain Rock under it can carry gutter water to the street side. Mason Sand fills the joints of a brick walk, and Fill Sand levels low spots before stone goes down.^[1]

For a swing set or a play fort, Playground Sand or Wood Chips cushion falls. On clay, put a few inches of #57 Crushed Stone under the play layer, with fabric between, so rain drains out of the box instead of turning the sand into a pond. Railroad Ballast, large and angular, holds the edge of a shed pad or a trailer spot where heavy loads park.^[1]

Homes in ZIP 78626 and Georgetown

The Census counts 17,865 housing units in ZIP 78626, with a median build year of 2010. Detached single-family houses account for 67 percent of them. Owners occupy 62 percent of the occupied homes in the ZIP.^[4]

Georgetown as a whole has 37,206 housing units, and 73 percent of them are detached houses. The town's median home was built in 2008. Newer yards often still need beds finished, a side yard covered in stone or a parking pad added.^[4]

Texas road crews build to the Texas Department of Transportation's Flexible Base, Item 247, in its Standard Specifications for Construction and Maintenance of Highways, Streets, and Bridges (2024). The lesson for a home drive is the same as for a highway: a well graded stone layer, packed in lifts, spreads the load.^[5]