US Bridges

Watermill RD over Salt Br

Poor

Saline County, Missouri · S 21 T 50 N R 20 W · Structure no. 18022

Built
1977
48 years old
Condition
Poor
inspected March 2024
Type
Culvert
Concrete
Length
23 ft
2 main spans
Daily traffic
35
2024 count
Owner
County
County Highway Agency

About this bridge

Watermill RD over Salt Br is a concrete culvert carrying Watermill RD over Salt Br in Saline County, Missouri. It was built in 1977, so it is 48 years old, older than the Missouri average of 45.1 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 35 vehicles a day, roughly 10% of them trucks, projected to reach 39 by 2044. The structure is 23 ft (7 m) long and 30 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesWatermill RD
CrossesSalt Br
LocationS 21 T 50 N R 20 W
RouteCounty Highway 170
CountySaline County
StateMissouri
Coordinates39.10686, -93.10751
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Channel and channel protection3 SeriousLoss of section, deterioration, spalling or scour have seriously affected primary structural components.
Culvert4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating54.6 US tons
Inventory rating17.9 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckConcrete, cast-in-place
Main spans2
Design loadOther
Structure length23 ft (7 m)
Longest span11 ft (3.4 m)
Deck width30 ft (9 m)
Roadway width28 ft (8.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic35 (2024)
Projected traffic39 by 2044
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$225,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Watermill RD over Salt Br built?

It was built in 1977, making it 48 years old in 2025.

What condition is Watermill RD over Salt Br in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in March 2024.

How much traffic does Watermill RD over Salt Br carry?

About 35 vehicles per day (2024 count), of which roughly 10% are trucks.

How long is Watermill RD over Salt Br?

The structure is 23 ft (7 m) long with a longest span of 11 ft (3.4 m) and a deck 30 ft wide.

Who owns Watermill RD over Salt Br?

It is owned by the County Highway Agency.