I'm in Castle Rock, CO at 6500' ... Zone 4-5.

They recently completed a drainage project through my yard, which very efficiently drains most of the water underground, but there is also an emergency (backup) swale which is almost never used for major water, but does serve to drain my own yard and my neighbors.

This swale drains to my curb and there is a double curb drain chase (drains under sidewalk, sidewalk has two steel plates over it.

The front ~60' of this swale is a grass lines swale which is in the middle of my yard. The problem is the last 15' doesn't drain completely and is sustained by yard irrigation and supplemented by normal rainfall events.

The area in the center of swale (2-3' wide) and maybe 10-15' deep, retains between .5" and 1" of water perpetually.

It's becoming clear that my yard is perma-mush and is even starting to turn black. The sodded yard is great all around, but this area has too much water. I even discovered a couple toads (frogs?) yesterday, while attempting to mow this bog-like area.

My question to you expects is -- what can I do in this area? Can I make a bad thing into a good thing? The wildcard for me is that this area needs to be over-runable by more water in the event of a larger rain.

It also has to be over-runable by a larger drainage event (like a 50 or 100 year rain) ... but only if my underground system fails. Both are 100 year flow capable. The underground system is dual 15" concrete pipes. THe above ground swale is 12" deep with tapered sides and ~20' wide.

So I'm trying to figure out what would work, if grass does not. I'm wanting to keep most of my front yard, but maybe water loving plants would be a better choice??

Thanks in advance,
Scott

Front yard with grass installed (doesn't look quite this good anymore)

View of front curb chase and looking down swale that runs through my yard. The wet area is the last 10-15' before the curb chase drain. You can really see the wet area good in this picture. It's been wetter than this picture would indicate, because I wasn't irrigation my yard when this was taken. My neighbor was (a little), so this water is from his back yard irrigation. In the winter, this area get very wet after snow melts.

View of curb chase from same direction as the first picture, but prior to yard install:

This is the cobble lined swale in the back yard, it's also a catch basin, as its 2' deep and the front swale is only 1' deep.

The water flows under my fence and the fence is raised up about 8" to allow for the 100 year flood, in the even the underground pipes don't work for some reason.

The swale is a backup drainage system, the main one being underground here. It's all within a 30' drainage easement across my property. The inlet (and feeding swales for the hillside) is located on the lot behind mine.

I don't think any dry well or grade adjustment is going to fix the problem. A powered sump pump would probably work, but no idea how to do that and have it be reliable and run only when needed.

The problem with rock is that when its left wet like this, it grows weeds and becomes a maintenance nightmare.

So I was thinking -- instead of killing and pulling weeds all the time, or trying to mow (and grow grass) in a bog, maybe growing water loving plants here would make more sense.

It would be nice to turn this problem into something nice looking and like something I INTENDED as apposed to something I have to deal with.

Since Colorado is pretty dry, I have no idea if it would work or what to plant. It's just that xeriscaping is common, but this kind of thing, very uncommon.

Nice pictures. They really document your situation.

What you have is a rain garden, not a bog. There's a big difference. Rain gardens receive runoff after storm events (also after lawn watering). Rain gardens get fertilizer runoff from the lawns and can be nutrient rich. Bogs are nutrient poor.

See if your Colorado University has a horticultural extension program or if they support a Master Gardeners group. If so, your extension or Master Gardeners should have a list of rain garden plants that grow in your area. You also need to check with your City (if Castle Rock is a big city) or County zoning office to see what you are allowed to do on an easement. My guess is that the zoning office won't care as long as your don't build a structure or change the runoff grade. But it's better to ask before you plant. Also, bringing in a recommended plant list from the university extension carries a lot of weight.

With that said, my guess is that you can grow sedges, swamp milkweed (they attract butterflies), joe-pye-weed, coneflowers, little bluestem grass, and many more. Try to stick with native wet prairie plants. Native plants will require less maintenance. But you will still need to pull weeds. Weeds will be less troublesome the more that you pull them, but you will always need to patrol the rain garden.

Hope this helps.

Tom

Here are is the plan I am looking at:

And also

You have an excellent plan!

It's likely that your plan is going to set a standard for similar sized gardens in your town. It's a real quality design. The developer did a great job.

As for plants, I'll give you a few native plant ideas.

Native Grasses:

Little Bluestem, Schizachyrium scoparium. Nice clump forming grass that grows to 3 feet tall. Pretty orange gold cast to the stems in fall. Good winter interest.

Prairie Dropseed, Sporobolus heterolepis. Short round clump forming grass, maybe 1 foot tall. The tiny grass flowers smell like pop corn when they bloom in summer. Attractive low grow grass.

Native Forbs:

Swamp Milkweed, Asclepias incarnata. Showy reddish pink blooms that attract Monarch butterflies. Can be challenging to establish. It loves wet soil.

Blue Wild Indigo, Baptisia australis. Showy bluish purple spikes in late spring. Creates a round bushy 3 to 4 foot tall planting (after 3 years). Attractive leaves.

Eastern Purple Coneflower, Echinacea purpurea. Excellent flower color and upright habit. Attracts American Goldfinches to eat the seeds. Maybe 3 feet tall.

Prairie Smoke, Geum triflorum. Early spring blooming plant. The attraction is the seed heads, not the flowers. The seed heads produce a wispy pinkish tuft that dances in the wind and resembles fire and smoke on a prairie (well, it kind of looks like smoke). Very short plant that goes well with Prairie Dropseed grass.

Hope this helps.

Tom