You'll need drawings (plans, elevations, etc) to submit for permit, I would highly recommend you work with an architect or designer rather than the builder for the drawings unless the builder is design/build. 

The creek by my primary house is .7 feet from being at the 500 year mark as far as the elevation.

They wont flood there as its the highest elevation on the gulf coast in the US territory.

If you need to be more creative due to income, etc, then look to someone like 1stBank, Bank of the West, or Elevations CU. 

What is an elevation certificate and what are they used for?  

Matt, you had a lot of misinformation going on as well as uncertainty regarding whether home elevation would be required.

Homes  that are close to water are commonly in a flood zone, which requires additional insurance, unless you pay cash for the home.Finally, areas west and to the north (roughly speaking, areas north of route I-90 and west of route I-95) are in the snow belt because they're somewhat elevated.  

This elevated his concerns and was a bit more amendable.

Introduce yourself, give an elevator speech of what you're looking for, and ask for their advice. 

Im in Ventura county which is also an elevated housing market.