Sepulveda Basin Crime Rate Trends — Los Angeles
Sepulveda Basin is the flood-control basin behind Sepulveda Dam in the central San Fernando Valley — a 2,000-acre recreation area containing Lake Balboa, the Sepulveda Basin Wildlife Reserve, the Woodley Park golf courses, and the Sepulveda Basin Sports Complex. Almost no residential population in the polygon itself.
August 2026 was a quiet month in Sepulveda Basin. No tracked category produced a notable signal: no spikes, no sustained shifts, no rare events. Every category stayed within its normal range for the period.
The 12-month picture shows more movement. Aggravated assault rose 31.2% against the prior year, 21 incidents vs 16, the one category running clearly above its recent pace. Motor vehicle theft moved in the opposite direction, down 50.0% to 5 incidents from 10. Theft from vehicle, vandalism, other larceny, and robbery all edged lower year-over-year, but none of those moves was large enough to register as a structural shift. The net read for August is stability, with the aggravated assault trajectory the one number worth watching into the fall.
Notable signals 0
Nothing notable surfaced this month — every category sits within normal range against its baseline.
All categories, last 24 months
Each panel: recent monthly count vs. trailing 12-month context. MoM is the most recent month vs. the one before; 12mo YoY compares the trailing year to the year before that.
What's been quietly true for a year
Spikes get attention. Sustained shifts shape policy. These are multi-quarter patterns where the past 12-month total differs meaningfully from the year before — they often precede the baseline resetting.
No sustained shifts surfaced this month.
What next month likely looks like
Forecasts trained through August 2026, with a likely range we're 95% confident the actual count will fall inside. Categories with too little recent volume — or violent categories at the neighborhood level — show no forecast and are surfaced through signals above instead. See the methodology page for the gating rules.
Aggravated Assault
Too low-volume per neighborhood for a reliable point forecast — see the rare-event and streak-break signals above instead.
Arson
Below the volume threshold for a reliable forecast — too few incidents in recent months to project from.
Burglary
Below the volume threshold for a reliable forecast — too few incidents in recent months to project from.
Homicide
Too low-volume per neighborhood for a reliable point forecast — see the rare-event and streak-break signals above instead.
Motor Vehicle Theft
Below the volume threshold for a reliable forecast — too few incidents in recent months to project from.
Other Larceny
Below the volume threshold for a reliable forecast — too few incidents in recent months to project from.
Robbery
Too low-volume per neighborhood for a reliable point forecast — see the rare-event and streak-break signals above instead.
Sexual Assault
Too low-volume per neighborhood for a reliable point forecast — see the rare-event and streak-break signals above instead.
Theft from Vehicle
Vandalism
How Sepulveda Basin compares
Peer neighborhoods picked by closest 12-month other larceny volume — a pragmatic v1 of peer matching. Demographic / housing-stock peer matching isn't built yet (we deliberately don't ingest income or race data alongside crime). Volume similarity has the right intuition: “neighborhoods experiencing comparable other larceny levels.”
Elysian Valley
16 incidents over the past 12 months — 4 above Sepulveda Basin's 12.
Open page →Manchester Square
16 incidents over the past 12 months — 4 above Sepulveda Basin's 12.
Open page →Hansen Dam
6 incidents over the past 12 months — 6 below Sepulveda Basin's 12.
Open page →Recurring local terms (last 12 months)
Top terms in incident descriptions for Sepulveda Basin, excluding generic crime taxonomy. Useful as texture — what kinds of specifics show up here that don't show up elsewhere.
Hour-of-day, day-of-week, and seasonality
Distribution of bucketed incidents in this neighborhood across the full analysis window. Useful for routine context — shopping-strip thefts vs. late-night assaults read very differently when you can see when each typically happens.
How we built this page
Counts from March 2024 onwardrun roughly 10 to 20 percent below LAPD's command-staff totals citywide. LAPD's legacy crime feed froze after a late-2024 cyber incident, and the replacement NIBRS feed has been shipping fewer rows than LAPD's own statistics show. The shortfall is most visible in homicide and in dense south-LA neighborhoods, because the new feed lacks coordinates and resolves location through reporting districts. Trend direction is still meaningful; absolute levels are not directly comparable to LAPD's headline figures.
Data → Anomalies → Forecast → Page
Incident data is pulled from LAPD's open feed on the LA City Open Data portal — the NIBRS-coded feed from 2024-03 onward with UCR backfill to 2020. Mapped to 10 NIBRS-aligned categories and aggregated to neighborhood × category × month.Anomalies are surfaced using strict thresholds (~p < 0.01). Forecasts are Prophet with low-count gating; violent categories at the neighborhood level skip the forecast and show rare-event / streak signals instead.
Spike rule: 12-mo total > baseline mean + 2.5σ AND ≥ 20 incidents AND 6-mo confirms. Drop rule: 12-mo total < baseline mean − 2.5σ AND baseline mean ≥ 20. Rare event: any incident in the last 90 days, no prior comparable in ≥ 5 years.