Cull Canyon Lagoon
Castro Valley, California · on Cull Creek · Cull Canyon Regional Recreation Area
Verified · 4 independent sources · top-verified
- WATER
- reservoir
- ACCESS
- Designated swim area
- FEE
- $3
- SEASON
- May
About Cull Canyon Lagoon
Cull Canyon Lagoon is a 1.5-acre swim facility operated by the East Bay Regional Park District (EBRPD) inside Cull Canyon Regional Recreation Area in Castro Valley, California. The lagoon is separated from the larger Cull Creek reservoir by a secondary dam and is run as a lifeguarded, fee-based swim complex with a bathhouse and sandy beach, seasonally from around Easter/May through Labor Day weekend.
The recreation area sits in a 360-acre canyon formed by damming Cull Creek in 1963; the swim lagoon is a separate, shallower impoundment behind a secondary dam that keeps its water level constant even as the main reservoir experiences seasonal draw-down. The design won the 1966 Governor's Design Award for Exceptional Distinction in landscape/recreational development, and the site includes lawns, a sandy beach, and picnic areas outside the swim complex.
Swimming at Cull Canyon Lagoon
Swimming takes place in an engineered, lifeguard-supervised lagoon with a sandy beach and "much shallow water for kids," per Wikipedia's description sourced from park materials; this makes it well suited to families and casual swimmers rather than open-water or deep-water swimmers. It is a managed, fenced swim facility (entry fee, capacity limits) rather than an informal natural swimming hole.
How to get to this swimming hole
The park address is 18825 Cull Canyon Rd., Castro Valley, CA 94552; EBRPD describes it as a short drive north from Interstate 580 via Cull Canyon Road.
Parking: On-site parking lot at the park; no parking fee. Parking lot hours are 8am-10pm (March-November) and 8am-8pm (December-February); park curfew is 10pm-5am unless otherwise posted.
The hike in
The swim complex is directly adjacent to the on-site parking lot at the Cull Canyon Road entrance; EBRPD's official materials describe no trail walk needed to reach the lagoon itself. The park does connect to the multi-use Chabot-to-Garin Regional Trail, which runs along Cull Canyon Rd starting at Heyer Avenue, drops toward Cull Creek, then continues about six miles through EBMUD land (hiking permit required) to the Willow View Trail into Anthony Chabot Regional Park -- but that is a separate hiking/biking corridor, not a path to the swim lagoon.
Three pedestrian/bike walk-in entrances (Heyer Avenue, Columbia Drive, Columbia Drive North) exist for visitors not arriving by car.
Plan your visit
Bringing kids
Good for kids
EBRPD's official swimming page describes the complex as 'ideal for families with small children, who will enjoy splashing in the shallows and playing on the white, sandy beach' of the chlorinated swim lagoon; swimming is lifeguard-supervised, and free beach wheelchairs are available on a first-come, first-served basis for accessibility.
Parking
Free
On-site parking lot at the Cull Canyon Road entrance; no parking fee. Parking lot hours: 8am-10pm (March-November) and 8am-8pm (December-February); park curfew is 10pm-5am unless otherwise posted. Three walk-in entrances (Heyer Avenue, Columbia Drive, Columbia Drive North) also exist for visitors arriving on foot or by bike rather than by car.
Restrooms
Yes
On-site bathhouse at the swim complex (per EBRPD's official park and swimming pages). EBRPD bathhouses at this type of facility typically include restrooms and changing rooms; the exact fixture type (flush vs. vault) is not specified on the official pages.
Water clarity
Clear
EBRPD's official swimming page explicitly calls it a 'chlorinated swim lagoon'. It is a maintained, pool-like facility rather than natural creek or reservoir water, so clarity is not weather- or runoff-dependent the way an open swimming hole would be. No independent visitor reports on water clarity could be found.
Hours
Swim facility is seasonal: May 16-31 open weekends/holidays, June 1-Aug 14 open daily, Aug 15-Sept 27 open weekends/holidays (season ends Sept 27). When open, swim complex hours are 11am-6pm (water closes 5:30pm). Park/parking-lot hours are 8am-10pm (Mar-Nov) and 8am-8pm (Dec-Feb); park curfew 10pm-5am unless otherwise posted.
On the water
Restrictions: No boating or paddling craft at Cull Canyon Lagoon. It is a small (1.5-acre), fenced, chlorinated, lifeguard-supervised swim complex rather than an open reservoir. EBRPD's district-wide 'Watercraft Permitted by Park' table (ebparks.org/recreation/boating) lists only Contra Loma, Crown Beach, Del Valle, Lake Chabot, MLK Shoreline, Quarry Lakes, and Shadow Cliffs as watercraft-permitted parks; Cull Canyon does not appear in that table at all.
The nearest EBRPD watercraft rental facility is the Lake Chabot Marina (a separate water body, Lake Chabot), which per the same official boating page rents canoe/kayak, pedal boats, row boats, and electric motor boats (no paddleboards in its rental fleet). Exact distance from Cull Canyon was not confirmed this session.
Backstory
Cull Creek was dammed in 1963 to create the reservoir; the swim lagoon was built behind a secondary dam to keep a constant water level for swimmers. The design earned the 1966 Governor's Design Award for Exceptional Distinction in landscape/recreational development. The main reservoir (separate from the swim lagoon) has suffered severe sedimentation -- reduced from an original 30-foot design depth to roughly 6 feet by 2014, receiving an estimated 12,000-20,000 cubic yards of silt annually; a 2002-2003 dredging removed 290,000 cubic yards but proved insufficient, and the district has since weighed a lower-cost weir-notching option against full dredging.
Cull Canyon Lagoon: FAQ
Does Cull Canyon Lagoon charge a fee?
No parking fee. Swim facility fees: under 2 free, child (2-17) $3, adult (18-61) $5, seniors (62+)/disabled $3. The swim complex is cashless (Visa, MasterCard, Discover, or Tap to Pay at the kiosk); pre-registration is recommended for weekends and holidays since the facility reaches capacity early.
Is Cull Canyon Lagoon kid friendly?
EBRPD's official swimming page describes the complex as 'ideal for families with small children, who will enjoy splashing in the shallows and playing on the white, sandy beach' of the chlorinated swim lagoon; swimming is lifeguard-supervised, and free beach wheelchairs are available on a first-come, first-served basis for accessibility.
Do I need to hike to reach Cull Canyon Lagoon?
No significant hike is required. The swimming area is close to parking and access.
Where do I park for Cull Canyon Lagoon?
On-site parking lot at the Cull Canyon Road entrance; no parking fee. Parking lot hours: 8am-10pm (March-November) and 8am-8pm (December-February); park curfew is 10pm-5am unless otherwise posted. Three walk-in entrances (Heyer Avenue, Columbia Drive, Columbia Drive North) also exist for visitors arriving on foot or by bike rather than by car.
When is the best time to visit Cull Canyon Lagoon?
Swim facility is open seasonally: weekends and holidays from mid-May through late September, and daily from roughly June 1 through mid-August (swim season ends around September 27); hours when open are 11am-6pm (water closes 5:30pm).
What are the rules at Cull Canyon Lagoon?
No alcohol, glass containers, or portable BBQs allowed in the swim lagoon area. Dogs are not allowed in the swim facility. Once the swim facility reaches capacity on weekends/holidays, no further entries are allowed that day, with no exceptions.
What water body is Cull Canyon Lagoon on?
Cull Canyon Lagoon is on Cull Creek, a natural reservoir verified in USGS hydrography data.
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