In my May 3 post, I mentioned that I hired a new civil engineer to tackle the challenge of the threeplex DSSP, the development site servicing plan.  In very oversimplified terms, this plan deals with release of storm water from the property, into City storm sewer infrastructure. I published the initial draft in that post, it has now since evolved (for the better) into an approved plan.

The City tends to ratchet upward the requirement for these plans until it can become an insurmountable project killing hurdle.  What we had was a challenge to have less storm water runoff leave the threeplex site (when finished), than the old shack and garage that sat on the site for 50 years released.  This would prove a nearly impossible task and led to some negotiated settlement with the City, which, for once, thankfully, I was spared from having to take a lead role on.  

Early on we had some ugly solutions that just seemed to get uglier.  We had double walled pipes the length of the side yard connecting catch basins ($$), we had an underground concrete box to capture and release the water at the end ($$$), and we still did not meet the criteria.  I started adding up the cost of just the storage components and I was looking at a terrible number.

We started examining some solutions and we were led to more surface storage as ultimately being needed.  I've been watching the sites of another builder who does a lot of these and we took some ideas from his approach.  The end result is a concrete perimeter surface pond that can fill up during high flow events.  This may be really ugly when built, but at least I can control the timing, crew and design. I may be able to turn the inside of it into a xeriscape feature, or a community garden.  If I can turn the negative into a positive, it will definitely improve the streetscape vs a grass bottom box.  Maybe the future threeplex residents will like it as well?

The DSSP can be significantly complicated, but I am going to try and break it down into manageable pieces in future posts.  I have been studying these plans for some time now, and completed a couple already (both were nightmares, one was more like a 'bad dream' thanks to my contractor).  This topic is an area where I've yet to have benefitted from another builder giving me some practical guidance.  When facing a $20-$50k bill for managing water, it is critical to have someone who has done it before to help out.  There are many serious pitfalls in this process, and it can get out of hand very quickly.  I will share some info as I proceed to construction.