2006-12-01 tchapters23 25 27 - Laserfiche WebLink

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The Federal Government has a requirement that is meant to reduce water pollution from developed areas, specifically meant to reduce water pollution that can come from surface water into streams, lakes, the ocean, other natural bodies of water.This fits into a whole program covering what people call non-point source pollution. That is a point source is like a factory or mill that discharges effluent through a pipe into the ocean, or sewage treatment plant would be an example. Non-point source pollution is runoff from Ag fields, from construction sites, from subdivisions and the like. In the development phase, say when the ground is being cleared, that’s usually covered by what we call an NPDES Permit or national pollution discharge elimination system permit; and that’s usually tide to a grading or grubbing permit. The Federal requirements though also cover once there is construction on the site. So we were a little bit behind in doing this, and so we have to bring these amendments forward. One of the penalties is that if we don’t do this we could lose funding for the coastal zone management program which has about $300,000 a year coming into the Planning Department and supports some of the staff and our activities including our SMA permits that you see here, that some of the funding for doing that program is with this Federal funding. So the idea is that you have to not just let water run off directly into the ocean or into a river, it has to have some kind of filtration or treatment. And the method that fits in best to what has been done typically in Hawaii County is to have it go into drywells. The drywell is just a pit typically 10 to 20 feet deep that the surface runoff goes into the drywell; and then this has the effect of a treatment, or the filtration, that’s required. Because before, at the bottom of the drywell is rock, and then so the sediment and other suspended solids will get filtered out by the rock before it flows into any kind of bodies of water. The Federal government, the standards expect you to treat just the beginning amount of rain, the first amount of rain that falls, not cover all your flood waters with this. But the simplest way to do this was to just tie it into the County’s existing practices for flood control. And what the practices were -- And this is not, we’re putting this in an ordinance, this has been a matter of practice but it hasn’t actually been an ordinance of the County -- is that a developer is expected to provide drainage into a drywell system for what’s called the one-hour ten-year storm event. And what this is means is it’s the storm that has a 10 percent chance of occurring in any given year and the amount of rain you would expect in the heaviest one-hour of that storm. And actually it’s quite a bit of rain water. They have a chart for the island and it comes to two inches an hour in Kona and five inches an hour in Hilo. They have a chart that covers the whole island for this. So we are simply putting this requirement in formally in Chapter 23, you see the amendment there. The Subdivision Code currently has a very general statement of the developer/subdivider being required to provide flood control to the satisfaction of DPW, this is Section 23-92. This would make it much more specific and say that they have to provide the storm drainage and it has to go into a drywell, rather in a filtration system. So that covers all subdivisions. Then the Federal government, the standards also makes you require, require you to cover other kinds of urban development. And there are some significant kinds of development that don’t involve a subdivision. For example, an office building, apartment building, they don’t usually have a subdivision associated with that. It’s just one ownership. But you might have a big building that’s under, that’s being developed. So almost all those kinds of developments need a plan approval from the County. And plan approval is covered by Chapter 25 of the Zoning Code. It’s a stage where the Planning Department looks at a building. We had some discussion of plan EXHIBIT B 2