Chatsworth Reservoir Crime Rate Trends — Los Angeles
Chatsworth Reservoir is the drained municipal reservoir basin in the far northwest San Fernando Valley, decommissioned after the 1971 Sylmar earthquake. Now mostly fenced open space owned by LADWP — almost no residential population, but listed as a neighborhood unit by the LA Times Mapping LA project.
Two categories returned after a long quiet gap in Chatsworth Reservoir this month — robbery and theft from vehicle both registered streak breaks, meaning each surfaced after an extended absence. That is the full scope of movement: two signals, both of the same type, against a backdrop of three categories that recorded zero events.
The longer-term picture for the neighborhood is one of contraction. Burglary has fallen 100.0% over the trailing 12 months against the prior 12 — zero incidents compared to 9 — and vandalism is down 77.8%, 2 incidents against 9. Everything else was within normal range. The streak breaks in robbery and theft from vehicle are the only signals that broke from that otherwise quiet pattern.
Notable signals 2
Robbery
First incident since September 2023 — a 3-year gap ended this month.
Theft from Vehicle
First incident since February 2024 — a 2-year gap ended this month.
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 April 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
Below the volume threshold for a reliable forecast — too few incidents in recent months to project from.
Vandalism
Below the volume threshold for a reliable forecast — too few incidents in recent months to project from.
How Chatsworth Reservoir compares
Peer neighborhoods picked by closest 12-month robbery 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 robbery levels.”
Hansen Dam
1 incidents over the past 12 months — 0 below Chatsworth Reservoir's 1.
Open page →Shadow Hills
1 incidents over the past 12 months — 0 below Chatsworth Reservoir's 1.
Open page →Cheviot Hills
2 incidents over the past 12 months — 1 above Chatsworth Reservoir's 1.
Open page →Recurring local terms (last 12 months)
Top terms in incident descriptions for Chatsworth Reservoir, 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.