Master Planning The Other Watershed

Upper Montclair Basin Needs Your Help

By Brian Hyde

In the next few weeks, members of Denver stormwater and flood mitigation staff and their consultant team will begin the process of developing a master plan for the Upper Montclair Creek Watershed.

For several reasons, I am confident this will go very differently from the city’s far more controversial efforts for Lower Montclair Creek, which includes the City Park Golf Course. That project has been named by the city as the Platte to Park Hill.

 Bruce Uhernik of the city’s wastewater division said recently that they have defined the Upper Montclair Basin as that part of the watershed that drains into Ferril Lake, in City Park.

With that in mind, check out Map #1, below. This “big picture” view, showing almost all of the Upper Watershed, allows us to consider three important matters:

• Making sure we separate the master plan for the Upper Montclair Basin, to the maximum extent possible, from plans and activities downstream of 23rd Avenue. (I do not advocate ignoring the City Park Golf Course controversy; I do recommend keeping this new project separate from that controversy.)

• To take note of the areas of the Upper Montclair Basin that are within Greater Park Hill and those areas of the basin that are in other neighborhoods (Greater Park Hill Community, Inc. needs to work co-operatively with all of those neighborhoods, for the benefit of the watershed).

• To begin distinguishing between areas where potential flooding would be a nuisance and areas where potential flooding would be dangerous, perhaps deadly.

The map shows blue lines, which are lines of shallow flooding. They are narrow lines because shallow flooding in this watershed is primarily confined to streets and lands immediately adjacent to the streets.

The map also shows areas in orange. Blue represents areas of  “shallow” flooding, 18 inches or less. Orange represents areas of “deep” flooding, 18 inches or more. I will explain my reasoning regarding the depth of flooding criterion of 18 inches shortly.

Now it’s time to move from the broader, more contextual view to the specific or local view that is directly pertinent to Greater Park Hill. Map #2, below, focuses almost exclusively on our neighborhood.

Certainly, the areas of orange catch the eye, as they are intended to do. Those are the bottomlands where flood depths during a 1 percent or larger flood will exceed 18 inches.

Let’s talk about flood depths for a little while by examining hypothetical flood risk to me. I’m about 6 feet tall. So here we go, in approximate increments of 6 inches:

• 6’’ Top of ankles

• 12” Middle of calf

• 18” Just below knee

• 24’ Bottom of thigh

• 30’ Top of thigh

• 36” Hip

• 42” Waist

• 48” Chest

• 54” Armpit

• 60” Shoulders

• 66” Chin

• 72” Top of head

Somewhere between my knee and my waist, I believe I should be worried. Now, for a different perspective on flood risk, we’ll look at my kitchen and the adjacent family/dining area, again in increments of 6 inches, but starting at 18 inches:

• 18” Seats of dining chairs

• 24’ Armrest on couch

• 30’ Top of dinner table

• 36” Door handle

• 42” Top of roll-top desk

• 48” First shelf of built-in bookshelves

• 54” Bottom of upper kitchen cabinets

• 60” Second shelf of bookshelves

• 66” Clock on microwave

• 72” Top of microwave

I will submit that with children, grandparents, and people who face a variety of challenges in moving quickly and safely, 18 inches of floodwater could be the start of a problem.

I also submit that we should refrain from proposing alternative “solutions” for the orange areas this early in the planning process.

I’ll start the conversation about what we might do by focusing, instead, on the blue areas in the Upper Montclair Creek Watershed.

Continuing my April and May discussion of potential multi-function green corridors, here is an initial proposal: To modify portions of 16th Avenue, 19th Avenue, and 22nd Avenue in Park Hill to integrate floodplain/stormwater functions with vehicular traffic calming functions and with pedestrian/bike corridor functions.

We are just getting started, but the Upper Montclair Basin needs your help. Let me know how you’d like to participate.

Brian Hyde is an expert in floodplain management and stream restoration. He wants your feedback at westerly_connect_brian@comcast.net or 720-939-6039.