Swimming & paddling in Boulder
The main places to get on or in the water around Boulder, Colorado are Boulder Reservoir (a summer swim beach plus stand-up paddleboarding and kayaking), Boulder Creek (classic downtown tubing in summer), and Gross Reservoir (quiet non-motorized paddling), with swimming allowed only in designated areas.
Outdoor Boulder › On the water in Boulder
Where to get on the water in Boulder
Boulder isn't a coastal town, but on a hot day there's more water than you'd think: a swim beach, a creek made for tubing, and quiet reservoirs for paddling. Here's the honest rundown, with who each one is really for.
| Place | Activities | Who it's for | Dogs | Season |
|---|---|---|---|---|
| Boulder Reservoir | Swim beach, SUP, kayak | Families and swimmers who want a real beach day, plus paddlers. | Banned at the swim area May 15 to Labor Day | Late May to Labor Day |
| Coot Lake | Dog swimming, quiet walking | Dogs and their people (no human swimming here). | East and south shores only, Voice and Sight tag to be off-leash | Year-round, best in summer |
| Boulder Creek (tubing) | Tubing, wading | Anyone after a hot-day float straight through downtown. | Leashed on the adjacent Boulder Creek Path | Summer, once flows drop |
| Gross Reservoir | Non-motorized paddling, fishing | Paddlers and anglers who want quiet, motor-free water. | Check current Denver Water rules before you go | May 22 to Sept 30, 2026 |
| City outdoor pools | Lap swim, open swim, kids' features | Reliable, lifeguarded water when the lakes are cold or crowded. | Not allowed | Summer season |
Where to swim in Boulder
The one true swimming spot in town is Boulder Reservoir, where a sandy, lifeguarded swim beach opens for the summer. Swimming is allowed only in the designated swim area, and only while lifeguards are on duty (generally 10 a.m. to 6 p.m. daily from Memorial Day weekend through Labor Day). This matters: open-water swimming across the reservoirs is restricted, so you can't just strike out across the lake, and the beach can close temporarily for algae blooms. If you'd rather have lifeguarded water all season, the City of Boulder also runs two seasonal outdoor pools, Scott Carpenter Pool on 30th Street and Spruce Pool downtown.
Where to paddleboard and kayak in Boulder
For stand-up paddleboarding and kayaking, Boulder Reservoir is the hub. One rule trips people up: every watercraft needs a current City of Boulder Boulder Reservoir watercraft permit to launch, and that includes SUPs, kayaks, canoes, and inflatables, not just motorboats. If you don't own a board, rentals are available on site.
For quieter, motor-free water, Gross Reservoir up in the foothills allows human-powered boats: paddleboards, kayaks, and canoes. Note that Gross is in the middle of a multi-year dam-expansion project, so access has changed. For 2026 the reservoir is open for non-motorized boating May 22 through September 30, with recreation access shifting to the free North Shore Picnic Area, the boat launch relocated to the North Shore peninsula, and a free boater shuttle running Friday through Monday. Always check Denver Water's current rules before you drive up, since construction keeps changing what's open.
Tubing Boulder Creek, and how to do it safely
On a hot summer afternoon, floating Boulder Creek through the middle of town is a rite of passage. Many tubers put in near Eben G. Fine Park, at the mouth of Boulder Canyon on the west edge of downtown, and drift down alongside the Boulder Creek Path.
The creek deserves real respect, though. It's fed by snowmelt, so in late spring and early summer it runs cold, high, and fast, which is genuinely dangerous, not just chilly. Tubing is best later in the season once flows drop, and it's not recommended when the water is running high. A few non-negotiables the City of Boulder stresses: wear a personal flotation device, wear sturdy water shoes (the creek bed is rocky), and check the water level before you go. The Boulder County Sheriff can close the creek to tubing when it's unsafe, and the whitewater park just west of Eben G. Fine Park has rapids that aren't meant for tubes, so put in below it.
Permits and rules, at a glance
A quick summary so nothing surprises you at the water's edge. At Boulder Reservoir, a day-use entry fee applies April 1 through October 31, and every watercraft (including paddleboards) needs a Boulder Reservoir permit to launch; swimming is limited to the marked swim area during lifeguard hours. At Gross Reservoir, only non-motorized boats are allowed and access runs on the 2026 project schedule above. On Boulder Creek, there's no permit to tube, but flotation devices and checking flows are strongly urged, and the sheriff has the authority to close the creek. Coot Lake bans human swimming entirely.
Dogs and seasons
If you're bringing the dog, Boulder Reservoir is off-limits for them through the busy season: dogs are prohibited through the gates and along the south shoreline from May 15 through Labor Day. The better spot is Coot Lake, right next door and quieter, where dogs can swim on the east and south shores (not the west side or the wetland areas) and can be off-leash only if they're enrolled in the city's Voice and Sight tag program.
Season-wise, the water is a summer story. The reservoir swim beach runs late May through Labor Day, Gross Reservoir's boating season is set each year (May 22 to September 30 in 2026), and creek tubing waits for the snowmelt to settle before it's safe. The outdoor pools are seasonal too. Spring and fall are for shoreline walks, not swims.
Related guides
- Boulder Reservoir: the full guide to the swim beach, paddling permits, fees, and parking.
- Gross Reservoir: non-motorized paddling and fishing, plus the current dam-project access notes.
- Boulder Creek Path: the flat creekside path that runs alongside the tubing put-ins.
- Hiking in Boulder: if you'd rather be on a trail than in the water.
Recommended nearby
A few local spots we'd point a water day toward.
[CLIENT SLOT: featured paddleboard or kayak rental]
[One honest line: where to rent a board or boat for a day on the water.]
[CLIENT SLOT: featured Boulder Creek tube rental]
[One honest line: where to grab a tube before floating the creek.]
[CLIENT SLOT: featured swim lessons or coaching]
[One honest line: lessons or open-water coaching around Boulder.]
Swimming and paddling in Boulder: FAQ
Where can you swim in Boulder?
The main swimming spot is Boulder Reservoir's designated swim beach, open in summer while lifeguards are on duty. Open-water swimming in the reservoirs is restricted to that marked area, so you can't just swim anywhere on the lake. Coot Lake next door does not allow human swimming (it's a dog spot). For lifeguarded water all season, the city runs two seasonal outdoor pools, Scott Carpenter Pool and Spruce Pool.
Can you paddleboard or kayak in Boulder, and do you need a permit?
Yes. Boulder Reservoir is the main spot for stand-up paddleboarding and kayaking, and every watercraft, including SUPs, kayaks, canoes, and inflatables, needs a current City of Boulder Boulder Reservoir watercraft permit to launch. Gross Reservoir also allows human-powered boats like paddleboards, kayaks, and canoes during its 2026 season. Rentals are available near the reservoir.
Can you go tubing on Boulder Creek?
Yes, in summer once the snowmelt settles. Many tubers put in near Eben G. Fine Park at the mouth of Boulder Canyon on the west edge of downtown and float down alongside the Boulder Creek Path. The City of Boulder urges tubers to wear a personal flotation device and sturdy water shoes and to check the water level first.
Is Boulder Creek safe to tube?
It depends entirely on the flow. In late spring and early summer the creek runs cold, high, and fast with snowmelt, which is genuinely dangerous. Tubing is best at lower flows and is not recommended when the water is running high. The Boulder County Sheriff can close the creek when it's unsafe, and the whitewater park just west of Eben G. Fine Park has rapids that aren't meant for tubes.
Can dogs swim in Boulder?
The go-to dog swimming spot is Coot Lake, where dogs can swim on the east and south shores only (not the west side or the wetlands), and can be off-leash only if they're in the city's Voice and Sight tag program. At Boulder Reservoir, dogs are prohibited through the gates and along the south shoreline from May 15 through Labor Day, so summer swimming there is off-limits for them.
Sources
Facts and rules on this page are drawn from these authoritative sources:
- City of Boulder: Boulder Reservoir General Rules and FAQs (swim beach, watercraft permits, dogs)
- City of Boulder: Coot Lake (dog swimming, no human swimming)
- City of Boulder: How to Tube Safely on Boulder Creek
- Denver Water: Summer 2026 Recreation at Gross Reservoir
- City of Boulder: Aquatics (Scott Carpenter and Spruce outdoor pools)