Bridge conditions in Grundy County, Iowa
288 inventoried bridges · 77 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
Grundy County has 77 bridges rated poor out of 288 inventoried, a 26.7% share that puts it well above the national rate of about 7%.
- 77 of the 288 bridges in Grundy County, Iowa, are rated in poor condition (26.7%) in the 2025 National Bridge Inventory, as of .
- 120 bridges (41.7%) are rated good and 91 (31.6%) fair.
- The median Grundy County bridge was built in 1981.
- The busiest poor-rated bridge is Ia 14 over Black Hawk Creek (built 1931), carrying about 3,230 vehicles a day.
Good 41.7% · Fair 31.6% · Poor 26.7% of 288 bridges
Bridges rated poor
Every bridge in the county with a poor rating, busiest first. Poor means a major component is rated 4 or lower on FHWA's 0-9 scale; it is a repair flag, not a closure notice.
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Ia 14 over Black Hawk Creek | 1931 | 3,230 | Poor |
| FM over Blackhawk Creek | 1971 | 1,935 | Poor |
| First St over Blackhawk Creek | 1977 | 1,429 | Poor |
| First St over Blackhawk Creek | 1977 | 1,429 | Poor |
| FM over Wolf Creek Branch | 1975 | 1,394 | Poor |
| FM over Creek | 1966 | 707 | Poor |
| FM over Black Hawk Creek | 1979 | 687 | Poor |
| FM over Branch Beaver Creek | 1968 | 619 | Poor |
| FM over Blackhawk Creek | 1967 | 579 | Poor |
| FM over Mosquito Creek | 1977 | 501 | Poor |
| FM over Beaver Creek | 1973 | 501 | Poor |
| FM over Dowd Creek | 1972 | 491 | Poor |
| FM over Branch Black Hawk Creek | 1973 | 412 | Poor |
| FM over Black Hawk Creek | 1973 | 412 | Poor |
| FM over Branch Beaver Creek | 1966 | 393 | Poor |
| FM over Wolf Creek Branch | 1972 | 373 | Poor |
| FM over Wolf Creek Branch | 1972 | 285 | Poor |
| FM over Blackhawk Creek Branch | 1965 | 275 | Poor |
| FM over Beaver Creek Branch | 1932 | 265 | Poor |
| Nickel Ave over Munns Creek | 1955 | 216 | Poor |
| FM over Dowd Creek Branch | 1966 | 187 | Poor |
| FM over Wolf Creek | 1966 | 187 | Poor |
| FM over Blackhawk Creek Branch | 1956 | 177 | Poor |
| FM over Blackhawk Creek Branch | 1956 | 177 | Poor |
| Local Road over Branch Beaver Creek | 1975 | 100 | Poor |
| Local Road over Middle Fork Beaver Creek | 1952 | 99 | Poor |
| FM over Dowd Creek | 1964 | 98 | Poor |
| FM over Beaver Creek Branch | 1954 | 79 | Poor |
| Local over Branch of Blackhawk Crk | 1976 | 71 | Poor |
| Local over Black Hawk Creek | 1977 | 70 | Poor |
| Local Road over Branch of Wolf Creek | 1976 | 59 | Poor |
| Local over Dowd Creek | 1955 | 59 | Poor |
| Local over Black Hawk Creek | 1946 | 59 | Poor |
| R Ave over Branch of Blackhawk Crk | 1976 | 50 | Poor |
| Local over Wolf Creek | 1978 | 49 | Poor |
| Local Road over Branch Blackhawk Crk | 1976 | 49 | Poor |
| Local over Branch Wolf Creek | 1915 | 44 | Poor |
| Local Road over Branch of Wolf Creek | 1977 | 44 | Poor |
| Local Road over Branch of Wolf Creek | 1977 | 44 | Poor |
| Local Road over Branch Black Hawk Creek | 1973 | 44 | Poor |
| Local Road over South Fork Beaver Creek | 1948 | 44 | Poor |
| Local over Br Beaver Creek | 1978 | 44 | Poor |
| Local over Branch of Beaver Creek | 1953 | 40 | Poor |
| Local Rd over South Fork Beaver Creek | 1977 | 39 | Poor |
| Local Road over Middle Fork Beaver Creek | 1948 | 39 | Poor |
| Local Road over North Fork Beaver | 1981 | 39 | Poor |
| Local over Little Wolf Creek | 1976 | 33 | Poor |
| Local Road over Branch Black Hawk Creek | 1971 | 33 | Poor |
| Local over Mosquito Creek | 1983 | 33 | Poor |
| Local over Branch Blackhawk Creek | 1955 | 33 | Poor |
| Local Road over Creek | 1981 | 33 | Poor |
| Local over Branch Wolf Creek | 1956 | 30 | Poor |
| Local Road over Branch Black Hawk Creek | 1977 | 30 | Poor |
| Local Road over Creek | 1974 | 29 | Poor |
| Local Road over Munns Creek | 1971 | 29 | Poor |
| Local Road over Branch Black Hawk Creek | 1971 | 29 | Poor |
| Local Rd over Branch Blackhawk Creek | 1957 | 29 | Poor |
| Local over Branch Beaver Creek | 1971 | 29 | Poor |
| Local Road over Branch Black Hawk Creek | 1971 | 26 | Poor |
| Local Rd over Branch Black Hawk Creek | 1963 | 26 | Poor |
| Local Rd over Branch Blackhawk Creek | 1971 | 26 | Poor |
| Local Road over Black Hawk Creek | 1979 | 20 | Poor |
| Local over Munns Creek | 1957 | 20 | Poor |
| Local Road over Beaver Creek | 1978 | 20 | Poor |
| Local Road over Middle Fork of Beaver CR | 1976 | 20 | Poor |
| Local Road over Dowd Creek | 1977 | 15 | Poor |
| Local Road over Creek | 1977 | 15 | Poor |
| Local Road over Branch of Wolf Creek | 1953 | 15 | Poor |
| Local Rd over Branch Blackhawk Creek | 1956 | 15 | Poor |
| Local Road over N Fork of Beaver Creek | 1947 | 15 | Poor |
| Local over Br Beaver Creek | 1979 | 15 | Poor |
| Local Road over Branch of Wolf Creek | 1976 | 11 | Poor |
| Local Road over Wolf Creek | 1970 | 11 | Poor |
| Local over Small | 1978 | 11 | Poor |
| Local Rd over Black Hawk Creek | 1971 | 11 | Poor |
| Local Road over Beaver Creek | 1948 | 11 | Poor |
| Local over Branch Wolf Creek | 1914 | 5 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 20 over Stream | 1999 | 14,500 | Good |
| US 20 over Stream | 1999 | 13,500 | Good |
| US 20 over Stream | 1999 | 8,800 | Good |
| US 20 WB over Grundy Rd | 2000 | 6,800 | Good |
| US 20 EB over Grundy Rd | 2000 | 6,800 | Good |
| US 20 WB over Stream | 2000 | 6,800 | Good |
| US 20 EB over Stream | 2000 | 6,750 | Good |
| US 20 EB over SR T55 | 2000 | 6,500 | Good |
| WB US 20 over SR T55 | 2000 | 6,500 | Good |
| US 20 EB over Local Stream | 1999 | 6,500 | Good |
Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
All of Iowa: Iowa bridge conditions by county · every download on the data page.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.