Question
We have a new home in Parker Co and are planning the backyard landscape. I actually have two questions.  First is we have about a 25% grade as we are sort of the last house on the street and we get all the water flow for the rest of the street.  We also have a swell going through the middle of the yard (diagonally due to downspout) and are wanting to do a French drain.  Being novices, is a French drain something we should even attempt to try ourselves?    Second in regards to grade, it that something again we could level off ourselves?  If so how would we do that?  Again we are novices but definitely not afraid of the grunt work needed.   We want to level the actually "yard" part so it is so close to even as possible without impacting drainage too much.  

Thanks
Linda  

Answer
Its kind of a "loaded question", as there is are a series of numbers that you cannot just GUESS at.... one of the most important is how much water ends up on your property, and where does it go beyond your property lines.

It sounds like you have a drainage easement or catchment devise that conveys storm water across your property from other sources, which is not all that uncommon in subdivision design.

Unfortunately, it may not be yours to do with as you see fit.  Not knowing how many houses in your subdivision release storm flows onto your property, I wouldn't want to just hazard a guess.

Its called the "tributary area", and it will help determine what kinds of water volumes you are anticipating. It also helps to know what sort of environment you live in -obviously an area that get 30+ inches of rain/year has to deal with a lot more water than my dry, 6"/year desert region.

Parker County, TX beats us by 5-times the amount of rain - and I'll bet it all comes down at once!...)or is it Parker Co., Colorado?)  Civil Engineers just love this sort of stuff, and it may be time to check at least with the local city engineer to see to what extent you can "mess" with this channel...There may be some options, but it is best determined locally, not across the internet.  Not trying to dodge the question, just trying to keep you out of trouble, avoiding a "shoot-from-the-hip" answer to a potentially costly mistake!

I had one drainage channel redesign project in Virginia which looked innocent enough, but ended up carving up four adjacent lots and adding a *huge* drainage basin that took up 1/3rd of the property - all for a simple home-addition!  

For your information, I'll give you some links on what these structures look like (a swale & a French drain), but as far as pushing some dirt around over a weekend, it sounds like there needs to be a little more pre-construction checking, first.

The links:
Swale:

http://www.stormwatercenter.net/Manual_Builder/dry_swale_design_example.htm

French Drain Design/Construction:

http://landscaping.about.com/cs/lazylandscaping/ht/French_drains.htm

-Marc