The top reported proficiency rate is 65% in English language arts. The lowest is 53% in Math.
Original Research by School Decision on Sangamon Valley Intermediate Sch
Sangamon Valley Intermediate School serves grades 3 through 5 in Illiopolis, a small rural village in Sangamon County situated between Springfield and Decatur. The school is one piece of a multi-campus district; the district's primary school serves pre-K through 2 in nearby Harristown, while the middle and high schools are located in Niantic. The intermediate building shares its address on Matilda Street with the middle school on what the district calls its West Campus.
The school's recent state assessment results show mixed performance. In third grade, math and English language arts proficiency each fall just below the midpoint, while fourth grade sees a modest dip in math proficiency paired with stronger performance in ELA. Fifth grade presents a notably different picture: ELA proficiency climbs substantially, while math proficiency drops to its lowest level across the grades served. Science proficiency in fifth grade (the only grade tested in science at this school) sits near the middle. All grades showed strong test participation, with fifth and fourth grade achieving full participation. Overall, the school's proficiency index places it in the top quartile among Sangamon County school districts, a positioning that reflects solid fundamentals rather than exceptional performance; the county median for such an index is somewhat lower.
The enrollment is small for an intermediate school, and the student body is predominantly white, with very few students representing other racial or ethnic groups. No data on free-or-reduced-price lunch eligibility, special education, or English learner populations are publicly available. Students take the state's Illinois Assessment of Readiness in both math and ELA and the Illinois Science Assessment in grade 5.
Illiopolis itself has experienced steady economic decline over recent decades. The village's largest employer, the Formosa Plastics PVC plant, shut down in the early 2000s after a major industrial accident and was demolished years later. Prior employers such as the World War II-era Sangamon Ordnance Plant are now historical. The village markets itself on surplus municipal infrastructure and rail access rather than active new development. Housing activity is sparse: the median home value is below both the state and national benchmarks, and only a handful of homes list for sale at any given time. By contrast, property taxes in the district are rising; residents voting or relocating into the community should be aware that the district's 2025 tax levy increased meaningfully compared to the prior year.
The village itself is small and walkable in scope, with civic life centered around churches, the public library at Sixth and Mary Streets, and the school buildings on Matilda Street. A parents may want to look into what kinds of academic interventions or enrichment supports the school offers for students whose math proficiency lags, particularly in the upper grades served.
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