We received the following letter from NHDES regarding their visit to view the flooded areas from the storm of October 30, 2017:
Mr. Chandler, Mr. Patch, Ms. Garland, and Chief Roberts –
At the link below, you will find the site visit summary for the Saco and Rocky Branch Rivers that you requested.
Please let me know if you have any trouble accessing the document.
The summary, with pictures, was written strictly from the perspective of the fluvial geomorphologist, and describes the current river processes operating and their implications on infrastructure. Technical options for you to consider are also included, with discussion of their process implications should you choose to consider and undertake any of them. Your engineer on retainer can provide you design guidance and provide you information on involved costs.
Additionally, from the perspective of a floodplain manager, additional mitigation options relative to the properties we visited are available should you choose to consider them. As referenced in the report, the two properties directly downstream of the railroad crossing we visited will continue to experience flood inundation at the level of flows experienced during Irene or last October, irrespective of geomorphological factors. Mitigation projects such as elevating the buildings, or even acquisition can be considered. Personnel from HSEM and Jennifer Gilbert (NH OSI) can assist you with these if you choose to pursue them. Such options could be future considerations for the other property that we examined on the site visit if structural options with the river, as discussed in the summary, are not undertaken on the Saco River, and the flood chute system south of that house were to evolve as potentially described.
Hope that you find this information, and that contained in the fluvial geomorphology summary, helpful. If I can be of further assistance to you on issues related to the Saco or Rocky Branch Rivers, or have questions about the summary, please feel free to contact me.
Shane Csiki, Ph.D, CFM
Flood Hazards Program Administrator
New Hampshire Department of Environmental Services, New Hampshire Geological Survey
29 Hazen Drive, P.O. Box 95
Concord, NH 03302-0095