Flood Hazard Area Protections Control Development

Monday's special meeting of the zoning board of adjustment was devoted solely to the continuation of the controversial United Water property development hearing.  and supporters from the neighboring towns of Oradell and Bergenfield.  

Central among the concerns of the crowd was the issue of flooding. Angered by his reliance on DEP flood maps that date to 1980, members of New Milford's grassroots group , not only questioned his position on the validity of the 1980 map as a tool for determining flooding, but again questioned his position on the flooding of that property. 

Throughout the months of testimony, terms such as "flood hazard," "floodway" and "flood fringe" have been used in connection with the United Water property. But what do those terms mean and how do they affect the development of that property?

Dipple said the site is engineered for a 100 year storm event, meaning that the site is designed to handle 8.3 inches of water in a 24-hour period, but what exactly is a 100-year flood event? A 100-year flood is the level of flood water expected to be equaled or exceeded every 100 years on average. The DEP describes it as a flood that has a one percent chance of being equaled or exceeded in any one-year period.  

Dipple had  and that infiltration systems will be installed above and beneath the property to carry the water away from the property. That was countered by board attorney Scott Sproviero who suggested that practical experience may show that there will probably be events of flooding on the property. 

During Monday's meeting, Dipple agreed that overdevelopment may have played a part in exacerbating flooding; however, he said that the adoption of the storm water management rule in 2004 has enacted stringent laws designed to establish control on how development occurs in these areas. Stormwater rules are implemented by the NJDEP requiring the control of runoff from a site that is the subject of a site or subdivision application. For new development, this includes runoff quantity controls, runoff quality controls, and buffers around Category One waters--waters protected from any measurable changes in water quality because of their exceptional ecological significance, exceptional recreational significance, exceptional water supply significance, or exceptional fisheries resources. The Hackensack River is a Category One body of water.

Flood hazard area permits were established in response to development that increased the intensity and frequency of flooding by reducing flood storage, increasing stormwater runoff and obstructing the movement of floodwaters. It was purposed to foster responsible development of land that is currently undeveloped. 

Now, in order for a developer to construct in an area near a floodway, a flood hazard area permit from the NJDEP must be obtained. A floodway is designed to stand between you and the full force of a flood; a flood fringe is the outer portion of the flood hazard area. A flood hazard area is comprised of the floodway and the flood fringe. 

According to the NJDEP, the purpose of obtaining a flood hazard area permit is to ensure that the proposed development does not increase flooding. One way this is done is by requiring that the development be built at an elevation that is above the flood hazard area.

Dipple previously testified that elevation 14 is the regulatory flood elevation for New Jersey, and said that the elevation of Madison Ave. is 15, elevation for the proposed supermarket floor is 16, the parking lot in front of the proposed supermarket is elevation 15 and the area near River Road is elevation 23.

Flood Hazard Area rules emphasize limiting development near rivers and streams, in floodways and on flood fringes, as the most effective way to minimize damage caused by flooding. 

Do you think these protections are enough? 

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