Flushing, Sweeping, Preparing Roads for Chip Seal

County crews work hard, as summer rolls in, to make sure all roads are in good condition for summer activities. Water trucks, sweepers and vactor trucks hit the roads to clean up whatever debris has accumulated. A major part of the yearly program is chip sealing up to 75 miles of roadway each summer. These roads receive additional care in preparing them to have a new surface.

Repairing Soft Spots

When soils have dried out, County crews repair soft spots, digging them out, improving drainage and putting in appropriate fill, often gravels, to establish a more stable roadway.

Chip Seal

Chip Seal is a process of laying down a sticky oil and following up with small angular rock. The process provides an excellent, cost-effective wearing surface for County roads. Chip seal has a life span of about 7 years, after which it quickly deteriorates. As a result, roads are generally chip sealed when they still appear in good condition. However, if we let them go for a few more years, cracks, pot holes and other issues would quickly develop.

Cowlitz County assists cities and public facilities by chip sealing their roads and interior roads/parking areas. This is done using interlocal agreements and generally is a cost effective option for smaller entities.

Paving & Crack Sealing

Although most asphalt paving is completed by contractors, Cowlitz County does pave parking areas and small patches using our paving machine. Asphalt paving is a good option when a surface repair is needed, but it must be adequately and appropriately compacted, with correct air temperatures, in order to set up properly. Crack sealing is similar to paving but uses an oil that binds into the crack and allows for a shorter term solution to cracking roadways.

Paint Striping

Paint striping, and prepping for paint striping, is a time-intensive process. Prep requires the roads to be swept and clean prior to the paint truck coming through. The paint truck moves slowly and paint stripes are renewed every other year - that means approximately 200 miles of striping are conducted annually!

Culvert Repair and Replacement

County crews frequently repair damaged or otherwise unsuitable culverts throughout the County. Culvert repair and replacement keeps water moving in the fashion designed when the road was built - and in many cases, dramatically improves it. Additionally, when culverts are replaced they are replaced to current fish passage standards and through time, the County will be fully compliant with fish passage standards.


Mowing occurs throughout the year to keep vegetation down so drivers can see pedestrians, wildlife or oncoming traffic.

Ditch Cleaning

After a winter of heavier rainfall, debris and other materials fills up ditches and makes them shallower. During the spring, crews re-establish ditch depths, which allows the ditches to carry more water during the following year.

Shoulder Repair

A road's gravel shoulder is important for several reasons, but a major reason is that it strengthens and supports the pavement adjacent to it. A shoulder in good repair allows a driver to drive off to the shoulder and back on without damaging the pavement. Shoulder repair is conducted during winter because plants are not growing and crews are able to do this even in poor weather.

Reflective Button Removal

Reflective buttons are used in many locations and must be removed on roadways that will be resurface with either chip seal or asphalt paving during the summer season. The buttons are removed in preparation for that activity.

Hydroseeding and Erosion Control

Where needed, hydroseeding (seed mixed with a glue like substance) and erosion control are set up to help retain soil and reduce sedimentation downstream of the site.