Help with Cleaning really bad water runoff in my small yard

I've got an interesting challenge that I'd love to solve in my backyard.

I live in a subdivision in Carlsbad, CA. About 13 years ago, my yard and neighborhood was cut out of a hill.

My house sits on 1/5 of an acre I believe. The back yard has a flat area that is about 60 feet wide by 45 feet to the back of a retaining wall. From there my property is a steep hill - about a 40% grade. The hill is 60 wide by 80 long.

The bottom of the hill in the corner of my yard we have a problem with runoff. It is hard to say where exactly it is coming from but basically a geologist said that the water table has likely changed with everyone watering their yards and it is kind of a spring. Except that the water was tested and it was 9 times higher in Nitrates. Also it was really high in coliform.

I just got a soil sample test results back and posted a link to it below. The area is always wet even though it is connected now to a drain that goes to the front yard (probably wet because it is mostly clay with some loam). Also it has been wet for 8 years so it isn't surprising to me that they found HIGH salt content. The grass in the back yard died years ago. We replaced it a few times but it kept dying. Thinking back, there was always a layer of white over the dirt that extended 3-4 feet out front the hole.

https://www.dropbox.com/s/ytg0thg2xp...3-1-2013.pdf?m


Would love to know based on this information what to do!

I was thankful there weren't more heavy metals. Way too much Chlorine. The water just beyond the hill is reclaimed water so I'm wondering if that is part of the reason it is so high in chlorine. How can I repair the land in that area? What do I grow ? How can I desalinate the soil?

Thanks!
Sheri

The dropbox link did not work can you repost the link without the ... in it.
So the good thing about your spring is that it is high in nitrates.
The bad it is high in salt, most of the SW/cali soil is high in salt so that is not really surprising.
I would plant every/anything in the mint family (mint, thyme, rosemary, oregano, sage, basil, etc) they dont mind the salt that much. Plantains (Plantago spp.), and also the beet family ( spinach, beets, chard, quinoa, and sugar beets, amaranth) too.

You could also plant saltbush, it will store the salts and then you can dump it off property to lower your property salt level.
Try mulching the area it lower the odds of you getting more white salt deposits.
You can also plant beach plum in grown in salt water, sea kale, and pretty much any plant that has the word sea/salt/marsh/beach in its name, they grow in "salty" water.
Here are a few more salt tolerant plants. http://en.wikipedia.org/wiki/Halophyte

Try a few cold hardy banana they love the nitrates, not too sure about the salt, though, but they are high in potassium, so maybe.

Retaining wall? If you raise the land up and surround it with stone the the water will bypass your yard, or you can put a culvert in the raised and channel the water under you plants.


Perhaps if you posted a google earth pic of your yard, marking the slope in yellow and the flow of the water in blue people might be more help than I.

if there are no sewer piles or water pipes in the area..at least 100 feet..put in willow trees,they will suck up a lot of the extra water and clean it..cattails will also clean the water..that is what they use in a lot of water filtration areas..but the homeowners assoc might not allow?? possibly bamboo..but you wouild want that above retaining wall and rhizome barrier to keep it from the rest of the yard.

could dig a pond?? put in the cattails in shallow edge areas..but you'll need an overflow most likely