Quick Facts:
Location: Greendale, WI (Milwaukee)
Put-in: '42.9504, -88.0088' (between Richlonns/Goodyear Tire Center and Starbucks)
Take-out: '42.9475, -88.0158' (or use 5300 S.84th St, Greendale WI., then head east on N. Root River Parkway ... east of 84th St., north of Grange Ave.)
Shuttle Length/Drive-Time: 1 mile/3 minutes; otherwise (recommended) walk ~0.5 miles, dragging/carrying boat through woods
Character: Uniform width/depth cement ditch, with seven 'hydraulic jumps'/pour-overs, from 1'-3.25' (12' - 40').
Drainage area: less than 1 square mile (Yes, *extremely* small!)
Gradient: ~25' of drop in 0.45 mile, for an *equivalent* of ~55 FPM
Gauging: Get here while it's still raining (or IMMEDIATELY after) or you've missed it! (While we have linked this to a gauge, it is not really reliable to approximate flow here, as this will flash up and down more quickly than any gauge which updates online only hourly.)
Best I can tell, all waters here come from parking lots and street drains in Southridge Mall and immediately surrounding area. *Water quality may be 'iffy', being 100% urban runoff.* At S.76th Street it comes out from underground to run through just under a half-mile of cement ditch before flowing into the Root River.
Access at the upper end may be a bit problematic. A Starbucks and Martin Luther High School sit river-left. Richlonn's/Goodyear Tire Center sits river-right, and would be a better bet for parking. To keep things proper you'd have to talk to someone before parking a car in either lot. (Boaters should never assume it is ok to park without first asking and securing permission from business/church/school property, just as from other private property. Failure to get permission to park at a business, while not doing business at the business, is technically trespassing, and they would be within their rights to have you ticketed and/or towed.)
The take-out area may also be contested, as a Milwaukee County ordinance (by every possible interpretation I can make) prohibits launch, landing, or 'touching upon the shore' with 'any float, boat, or watercraft' at any spot not designated by the county as a landing spot (unless you have written permission from the parks director). While it is unlikely to be a priority enforcement issue, if you choose to go for this, it may still be best to keep a low profile ... spend as little time as possible to get on, get done, and get gone.
So ... why put this section on here? Well:
(1) In case some paddler becomes otherwise aware of it and thinks they've discovered an 'unknown' hitherto unrun bit of whitewater (I.E., a 'first descent'), and
(2) because it is obvious (from debris lines on shore and in the trees) that it does occasionally get enough water to be runnable, and
(3) because it has more jumps in less distance than any other area run! (A total of *seven hydraulic jumps (cement ledges): one at 1' (which will be inundated at boatable flows), one at ~40', and four at ~3'*. NOTE: Heights listed are height of cement ledge when dry. With boatable flows, effective height of drops will differ significantly ... being less in most cases.)
This cement ditch is very narrow and shores are heavily wooded (trees and shrubs, mostly non-native invasive buckthorn). It is extremely likely there will be branches (live or dead) overhanging or lieing into the flow. Since there will be no eddies, there may be no reasonable way to avoid becoming snagged/entangled by any obstruction in the stream!
For the above stated reasons, it is virtually mandatory to walk the entire section before putting on! This is best done if you forego vehicular shuttle, park at the take-out, and carry/drag (through thick buckthorn woods) up the river-left/south side of the stream. (Having a loppers or pruning saw in your boat might be advantageous, in case there are branches needing to be cleared en route up. It may be necessary to forego the uppermost put-in and just put-in downstream of any snag you find and can't remove.)
BTW, on the carry-up, one *could* go upslope of all the buckthorn woods to find a much easier walk on the Martin Luther High School property (alongside of tennis courts and running track areas). However, that would not serve the purpose of doing a thorough check for blockages and safe boating passage, and it would make you highly visible as you commit a trespass on private school property.
One final note: This could easily be paired with Villa Mann Creek (about 5 miles away), or as prelude to catching other bigger runs (Honey, Underwood, MenTosa, Mke/Mke) which will be runnable any time this is. (Though, frankly, Southridge Ditch is more fun, so you could skip Villa Mann and just get on to H/U/MT/MM).