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Difficulty I-II
Length 14.99 Miles
Flow Range 90 - 450 CFS
Flow Rate as of: 36 minutes ago 129 [CFS] 👍 ℹ️ ⚠️
Reach Info Last Updated 01/28/2019 8:52 pm

River Description

The entire course of Seneca Creek stretches many, many miles from the headwaters of Great Seneca Creek in Damascus Maryland through the cities of Gaithersburg, and Germantown and on down through Darnestown and Seneca, Maryland to the Potomac River. While not the action-packed whitewater trip that most users of this site are used to, it does offer a nice float trip for beginners with a few navigation and stability challenges thrown in for fun. The creek itself is maintained by a very few volunteers who work in conjunction with the MD park service to remove strainers, but often has large amounts of wood in certain less-maintained stretches which can present a complete set of challenges all their own. The park office can be reached at (301) 924-2127 if you want to report a strainer.

Seneca creek can be run in many different sections thanks to the many access points throughout the course of the creek. Above 120 CFS, Riffle Ford Road to Black Rock Mill Road will have the most class I-II action per mile, and Rte. 28 to Riley's Lock Road will hold its water a little longer than the rest of the creek remaining scrapy but runnable down to 70 CFS or so. Upstream of Riffle Ford road, a better minimum CFS might be 280. Upper levels are uncertain, but above 450 CFS the creek will get pushy and most of the fun will start to wash out.

The water quality of this section is generally good. Sediments and pollutants picked up in the more populated areas have, for the most part, dropped out of the water by the time they reach the old Black Rock Mill and the bottom of the creek is clearly visible through most of the trip with the exception of some deep and long pools behind two low dams on the trip. 

Access is reasonably good as is the ability for rescuers to reach those in trouble thanks to the Seneca Greenway Trail running parallel to the creek for most of its length as well as several access points from local roads which can bring vehicles close to the creek for either rescue or simply cutting the trip into more manageable chunks. 

The section below River road is mostly slackwater which flows very slowly to the Potomac past Riley's Lock and the Seneca Creek Aqueduct. You have the option to take out at Berryville Road, but parking is limited and tight. You also miss the chance to see the beautiful Aqueduct at the take-out if you choose to end the trip at Berryville Road. 




Rapid Descriptions

Rte. 355 (Frederick Road) Put-in

Class - N/A Mile - 0
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Park at Great Seneca Park 355 Parking lot and put in under the 355 Bridge

Waring Viaduct

Class - N/A Mile - 1.42
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The Waring Viaduct is a stone railroad bridge built in 1906 by the Baltimore and Ohio Railroad that is still in use today

Riffle Ford Road Access

Class - N/A Mile - 4.26

Park at the Seneca Creek State Park lot and put in just upstream

Rte. 118 (Germantown Road) Access

Class - N/A Mile - 6.59
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Pull off on the side of the road. Access is upstream on river left. Only enough space for two or three cars.

Black Rock Rapid

Class - II Mile - 7.7

The creek spills through natural stone and the foundations of an old dam just before Black Rock Mill. Follow the wave train on river left and watch out for swimmers in the pool below.

Black Rock Mill Access

Class - N/A Mile - 7.71

Put in at the old Black Rock Mill on Black Rock Road.

Rte. 28 (Darnestown Road) Access

Class - N/A Mile - 9.3
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Park at the Seneca Creek State Park lot. The old road leads directly to the Darnestown Road Dam

Darnestown Road Dam

Class - II Mile - 9.3

Low head dam that stands just a few feet high underneath the Route 28 bridge. Either flood control or possibly covering a water or sewer line that runs along the road. Best taken head on just right of center where a tongue forms. Expect some scraping at lower levels and a smoother ride at higher levels.

Tschiffely Mill Dam

Class - II Mile - 12.95

The tumbledown ruins of a stone and mortar dam built to divert flow from the creek, across the peninsula, and into the mill at Seneca Ford (present day River Road). Expect it after crossing the first long, deep pool on the creek when you can see a distinct horizon line. You will not hear the rapid until you are almost on it. Easily scouted from river right, you'll want to check it out from the shore as it is a quick drop over lots of rocks. The locals often build a sluice out of the loose rocks in the summer for tubing. 

Berryville Road Access

Class - N/A Mile - 13.11
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Quick access to the stream, and  a good place to check the water level before committing to the trip. Park along the side of the road and walk the trail upstream to the ruins of the Tschiffely Mill dam. If there is enough water for you to make a scraping descent of the dam, you'll have enough water for the whole trip. 

Riley's Lock Take-Out

Class - N/A Mile - 14.99

Public boat ramp with access to the Potomac River


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Mike Martin
2 months ago

Seneca Creek Update *Seneca Creek park rangers just completed chain saw certification from MD DNR and plan to help keep Seneca clear of strainers and /or portage trails clear and marked. The park has acquired a new fleet of canoes and rec boats and has a draft plan to expand their paddling program from just at the lake to include the creek too. Pending approval from Annapolis, they expect to be able to roll out the program this summer. Meanwhile, here’s the latest strainer report: Riffle Ford to Black Rock Rd THREE river-wide tree blockages that required portaging all of which involved steep banks I'd call the portages class three -- 10' elevation gains and a lot of elbow grease to complete. The logs are huge; I don't think the park can cut them easily cut them out. I'd stick with the section from 28 to Rileys while it's reportedly clear. Black Rock Rd to 28: One massive log jam that had a long, easy drag around on River left earlier this spring but it now badly overgrown. The park may cut a new portage there on river-right, but for now I'd say Rt. 28 is the head of navigation. MD Rt 28 to Riley’s Lock: Currenlty clear of river-wide blockages! In addition, the park staff has removed the logs and flotsam that made the Berryville PI/TO a bit of a pain.

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Mike Martin
10 months ago

Hi all, here's the latest strainer report that I got from a Seneca Creek State Park staffer on 10/22/18: "The last report on Seneca Creek that I got was that the last big rainstorm all but cleared out Black Rock to Berryville, but that Riffle Ford to Black Rock (Which I agree with you is the better section) has become fairly jammed up. Fortunately, we are making plans to do a day of strainer removal some time soon, since a logjam above Riffle Ford has blocked off enough water to threaten to erode the bank enough to threaten one of our trails." It's great to see that a few park staffers have taken to paddling the creek on their off hours, and it was a pleasure to meet and paddle with them when CCA put together a trip for them last summer.

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Mike Martin
11 months ago

I've run Seneca Creek twice this summer with several Canoe Cruiser's Assn, leaders and SCSP staff to assess the strainer situation report the following as of late August. The Creek is mostly open with a few easy drag arounds/ drag overs, and a few duck unders/tight squeezes, but beware of the following: A massive, newly downed scycamore slipped off the bank earlier this year, and it's river-right root ball may collect wood. The tree blocks enough of the creek that the river-right banks got carved out during the last high water event so that logs clogging its channel got washed out as of late August. If more collect there (about two miles below Rt. 28), the best portage is on river-left, with fairly easy egress and reentry. Below there, about a mile above the Berryville Rd. access point, a new, river-wide strainer presents a more serious challenge, given the steep banks and its propensity to pile up any wood that floats into it. At the 80 or so CFS we had, we were able to hump and over some of the wood, then swim our boats through the rest of the pile. No problems below. With more high water coming from Hurricane Florence, the situation will likely change in mid Sept. I'll try to post an update an photos later this month. Meanwhile see the CCA Facebook page for phots from our last trip.

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Tom Lippo
5 years ago

Ran the Seneca from Route 28 to Rileys Lock at 130 cfs on July 13, 2014. Absolutely beautiful seemingly remote creek yet very close to civilization. Low water but passable. THANKS to Mike for a very accurate trip report in June. I used the passageway you cut (literally one-kayak wide) which would have been challenging at any higher level. Now another tree is down (probably in the last day or two) but passable. Creek splits at approx. mile 4-5. Right channel is completely blocked by the broken-off top of a large tree upside down in the water - a BAD strainer. Easily portaged but at higher levels you will be nearly on top of it before you can exit. The other channels may be clear (I didn't backtrack to run them). So do not choose the right-hand channel at the split. NOTE: Several other branchy trees are down at various points along the route near to shore and parallel to the current BUT at some spots the natural current flow wants to push your boat into them = easily manageable but potentially dangerous for beginners or anyone not paying attention because of the consequences of getting sucked in. Stay alert but enjoy this beautiful stretch of "remoteness"! I was the only one there on a hot summer Sunday in July...!

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Mike Martin
5 years ago

The trip report below reports only one strainer between Rt. 28 and Riley's lock. Mike, Here's the TR. For me pretty much a PFD. Very impressed at its beauty & isolation. The hole we made in the single downed tree blocking the creek - is passable only by kayak - it took us 20 minutes to saw our way through. - Alf SENECA CREEK 300 cfs 5 boats Miki leads - Sat, 1 June 2014 For our part, I came along with Miki and Barb and a couple Doug and Lisa on the Seneca Creek - which I hadn't been on since a Jim Finucane clean-up in 2001. Our cfs was 300 - only one strainer, which we sawed our way through. In at 4:10 - out at Rileys Lock at 6:30. Fine level, scarcely ever touched bottom. I was most impressed that such a pretty creek is open and available; my notes from 2001 say that there were about 8 places needing cutting out. In fact, I'm thinking of getting out the tin canoe and taking Rita down! Sunny, cool.

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Mike Martin
5 years ago

I paddled Seneca Creek several times this spring and found it clear of strainers, between MD Rt. 28 and Riley's Lock, but rather strainer-choked between Black Rock Rd. and 28. However, the most recent trip on Seneca Was on May 11 -- a few days before we got the 3" rain dump on May 14-15. George, can you clarify what the strainer situation is now between 28 and the takeouts at Berryville Rd. and at Riley's? I now live about 4 miles from the Rt. 28 put in and will try to keep an eye on the creek, will post more when I get a chance to run or scout it.

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George Bassler
5 years ago

we paddled this reach on 5/23/14 lots of strainers/Trees block passage. from the black rock mill to rileys landing we had to portage around at least 20 riverwide strianers. most are very big trees that will take a lot of work to remove. river was low enough about 3.5 ft , that the strianers presented no big safety hazard but higher water trips would not be advised.

Gage Descriptions

The USGS gauge for Seneca Creek is located at Dawsonville (Darnestown) MD just downstream of the put-in at Black Rock Mill. Depending on weather conditions in the area, it is advisable to also review the Little Seneca Creek Gauge near Germantown as rain in the Little Seneca Creek basin will affect the flow from the confluence of Little Seneca Creek onward.

Directions Description

There is only limited parking at the put-in but ample parking at the take-out. If parking at the mill is taken, you can park along Black Rock Road on the north side of the creek.


13015 Rileys Lock Rd
Poolesville, MD 20837
Head north on Rileys Lock Rd toward River Rd
0.6 mi
Take the 1st right onto River Rd
0.7 mi
Continue onto Seneca Rd
2.8 mi
Turn left onto Darnestown Rd
1.7 mi
Turn right onto Black Rock Rd
Destination will be on the left
0.6 mi
16510 Black Rock Rd
Germantown, MD 20874


Alternatively, you can take Berryville Road which gives you an opportunity to see the bend in the creek below the Tschiffley Mill Dam ruins from the road.

No Accident Reports




article main photo

Upper Yough Access Depends on Everyone

Charlie and Sandy Walbridge

Many thanks those who have contributed to AW's Sang Run Access Fund on line. We raised over $1200 to pay for the porta potty and gravel. Thanks to you, we've maintained this site for the State of Maryland for over 20 years! Let's also give a special shout out to Don Millard, who has cut the grass in both Friendsville and Sang Run for many years to keep our access costs low. If not for him you might see a parking fee of $5 a head at both ends! Jeff Macklin Photo


Colin Abernethy


John Ford


Johnathan Ford


Revision #Revision DateAuthorComment
1202861 11/18/13 Colin Abernethy Pictures added to rapid/feature descriptions
1202860 11/18/13 Colin Abernethy n/a
1210928 01/25/19 John Ford updated stats
1210929 01/25/19 John Ford updated description
1210955 01/25/19 Johnathan Ford updated stats
1210956 01/25/19 Johnathan Ford updated stats
1210932 01/25/19 John Ford updated description
1210934 01/25/19 John Ford updated description
1210930 01/25/19 John Ford updated stats
1210957 01/25/19 Johnathan Ford updated stats
1211013 01/28/19 John Ford updated description