Bay Farm Island, Alameda vs Walnut Creek
Bay Farm Island, Alameda carries an effective property tax rate of 1.22% of assessed value and Walnut Creek carries 1.08%, both for fiscal year 2025-26. On one identical reference loan the monthly carrying costs are $9,917 and $9,733 — $184 apart, with Walnut Creek lower. To Oakland City Center at AM peak the fastest published commutes are 20 min by car from Bay Farm Island, Alameda and 27 min by BART from Walnut Creek. Every figure is an objective public metric or arithmetic on one, and names its source.
Bay Farm Island, Alameda (Alameda County) · Walnut Creek (Contra Costa County)
| Metric | Bay Farm Island, Alameda | Walnut Creek | Difference |
|---|---|---|---|
| Median $/sqft (SFR) | $750 | $800 | −$50 |
| Effective tax rate | 1.22% | 1.08% | +0.138% |
| Monthly cost, reference loan | $9,917 | $9,733 | +$184 |
| FiDi SF (Montgomery St BART) — BART | 45 min | 45 min | 0 min |
| FiDi SF (Montgomery St BART) — Drive | 40 min | 55 min | −15 min |
| Oakland City Center (12th St BART) — BART | 35 min | 27 min | +8 min |
| Oakland City Center (12th St BART) — Drive | 20 min | 32 min | −12 min |
| Sunnyvale / Mountain View (Sunnyvale Caltrain) — Drive | 55 min | 62 min | −7 min |
Difference is Bay Farm Island, Alameda minus Walnut Creek. Sources are cited on each submarket page.
Financed identically, Alameda (Bay Farm) costs $184 a month more than Walnut Creek — $2,208 a year, all of it tax. Alameda (Bay Farm) is modelled at 1.22% and Walnut Creek at 1.08%, which is the whole of the difference before either HOA or a district assessment is counted.
What the same money buys
Walnut Creek comps run $650-$750 per square foot; downtown condos and Rossmoor run $500-$650. Against that, bay Farm comps run $800-$900 per square foot detached and the high $600s for lagoon townhomes. At $750 and $800 per foot respectively, a fixed budget buys about 7% more floor area in Alameda (Bay Farm).
Carrying $1,600,000 in each
Holding the loan constant — $1,600,000, 20% down, 6.5% on a 30-year fixed, $2,400 of insurance, no HOA — Alameda (Bay Farm) totals $9,917 a month at 1.22% and Walnut Creek $9,733 at 1.08% — tax lines of $1,627 and $1,443. Harbor Bay Isle dues run $150-$200 a month depending on the village. No Mello-Roos in Walnut Creek, and most detached homes carry no HOA.
The trip each morning
To FiDi SF (Montgomery St BART): 35 minutes by ferry from Alameda (Bay Farm), 45 by BART from Walnut Creek — a 10-minute edge to Alameda (Bay Farm), or 1.7 hours across a ten-trip week. To Oakland City Center (12th St BART): 20 minutes by driving from Alameda (Bay Farm), 27 by BART from Walnut Creek — a 7-minute edge to Alameda (Bay Farm), or 1.2 hours across a ten-trip week. Bay Farm has no BART; Coliseum station is a 12-minute drive. Door to door from Northgate to FiDi is 55-65 minutes.
Hazard and insurance
Most of Bay Farm is engineered fill, so liquefaction is the standing disclosure. Creek flooding along Walnut Creek and San Ramon Creek appears on the NHD for lower lots. Pull the parcel's own mapping — CAL FIRE severity zone, FEMA flood panel, CGS liquefaction zone — and get a written quote before the contingency date.
Choosing between them
Bay Farm answers a townhome-pricing requirement with a flat, short bike commute. Walnut Creek is the Contra Costa option when the flats matter more than the view. Write the requirement down before the search: these two answer different ones.
Sources. Rate and payment figures: Alameda County Tax Rates by TRA FY 2025-26; Contra Costa TRA Book FY 2025-26, as composited in build/assets/metrics.json — unverified at tax-rate-area level, so read the bill. Minutes shown are AM-peak and door to door, from data/commute/static.csv. The per-foot medians are trailing and carry no appraisal weight; the neighborhood detail is first-hand broker observation.
Compare any two submarkets
| Metric | Bay Farm Island, Alameda | Walnut Creek |
|---|---|---|
| Median $/sqft (SFR) | $750 | $800 |
| Effective tax rate | 1.22% | 1.08% |
| Monthly cost, reference loan | $9,917 | $9,733 |
| Fastest to FiDi SF (Montgomery St BART) | 35 min | 45 min |
| Fastest to Oakland City Center (12th St BART) | 20 min | 27 min |
| Fastest to Sunnyvale / Mountain View (Sunnyvale Caltrain) | 55 min | 62 min |
Same reference loan on both sides; the tax line is the only variable. Commute figures are door-to-door AM-peak estimates. Sources are listed on each submarket page.
Bay Farm Island, Alameda detail
| Component | Rate of assessed value |
|---|---|
| Prop 13 general levy | 1.000% |
| County / city voter-approved bonds | 0.042% |
| School district measures | 0.178% |
| Effective rate | 1.22% |
| Mello-Roos / CFD | None recorded |
Source: Alameda County Tax Rates by TRA FY 2025-26 (Alameda County), composited in
build/assets/metrics.json.
Tax Rate Area not yet verified parcel-by-parcel — confirm the rate on the parcel’s own tax bill.
Walnut Creek detail
| Component | Rate of assessed value |
|---|---|
| Prop 13 general levy | 1.000% |
| County / city voter-approved bonds | 0.012% |
| School district measures | 0.070% |
| Effective rate | 1.08% |
| Mello-Roos / CFD | None recorded |
Source: Contra Costa TRA Book FY 2025-26 (Contra Costa County), composited in
build/assets/metrics.json.
Tax Rate Area not yet verified parcel-by-parcel — confirm the rate on the parcel’s own tax bill.
Bay Farm Island, Alameda vs Walnut Creek: questions and answers
- Which has the lower effective property tax rate, Bay Farm Island, Alameda or Walnut Creek?
- Walnut Creek, at 1.08% of assessed value against 1.22% for fiscal year 2025-26 — a gap of 0.140%. Rates are composited from county tax rate books; each parcel bill governs.
- How much do monthly carrying costs differ between Bay Farm Island, Alameda and Walnut Creek?
- $184 per month on the identical reference loan: Bay Farm Island, Alameda $9,917, Walnut Creek $9,733. Walnut Creek is lower. Principal and interest are held constant, so the difference is the tax line. Arithmetic only.
- Which has the shorter commute to Oakland City Center, Bay Farm Island, Alameda or Walnut Creek?
- Bay Farm Island, Alameda. Bay Farm Island, Alameda is 20 min by car; Walnut Creek is 27 min by BART. Door-to-door, AM peak. Source: data/commute/static.csv.
- What is the price per square foot difference between Bay Farm Island, Alameda and Walnut Creek?
- $50 per square foot: Bay Farm Island, Alameda $750, Walnut Creek $800. Single-family medians, trailing twelve months. A median is not a valuation of any specific property.