Floodplain map changes affect homes in LaPorte

By Cherry Sokoloski
North Forty News

Cork Drive in LaPorte boasts 16 homes. If changes in the 100-year floodplain maps go through as planned, all will be moved into the floodplain.

The street is in the Cotton Willow subdivision, southeast of Vern's Place. Shannon Drive, also in that neighborhood, will be affected as well if the changes are adopted. Some homes on Shannon Drive would be designated as being in the "floodway," referring to the area that experiences the most flooding in a 100-year event.

The proposed changes are outlined on new floodplain maps for Larimer County. They are the result of a recent study conducted by the county on a stretch of the Poudre River from Shields Street upstream to Watson Lake.

Ed Woodward, senior engineering technician for the county, said Cotton Willow is the only major subdivision in the Poudre study area, and thus the most impacted by the changes. The 100-year floodplain has also been widened in the gravel pit areas between Overland Trail and Taft Hill Road.

The new maps are not yet set in stone. A public comment period on the floodplain changes lasts until May 3. The county hopes to finalize the maps by Sept. 30, following approval by various local, state and federal agencies.

Cotton Willow isn't the only area in LaPorte affected by the changes. Trail's End, a planned development across from Vern's Place on land owned by J. Gale Moody of Eaton, is currently in the 500-year floodplain but would be designated as 100-year if the new maps are approved. Moody has received preliminary approval to divide the property into three lots. He has not yet filed a final plat.

There's a lot of interest in the new maps, because being in the floodplain costs homeowners money and limits what they can do with their property. The county held an open house to show the maps on Dec. 6, and despite a snowstorm, about 150 people showed up for the event.

The 100-year floodplain is divided into two areas: the flood fringe and the floodway. In the flood fringe, flood insurance is required when there is a mortgage on the property. Also, any new construction must be built at least 18 inches above the floodplain.

A person may not build anything at all in the floodway, including a home addition or a shed, unless Larimer County approves a variance.

By contrast, the county has no building restrictions for properties in the 500-year floodplain.

When drawing up floodplain maps, two factors are considered: the history of flooding for a given area and the ground elevation of properties in the area. Prior to the recent studies, the last floodplain data were collected by the Army Corps of Engineers in 1986, according to project engineer Rex Burns. The technology for measuring ground elevations has improved, he noted, leading to changes in the mapping. Engineers now use global positioning systems to arrive at more accurate contours and elevations.

Burns said about 600 properties are in the restudied areas, but he does not know how many would be affected by the proposed changes. Two sections of the Big Thompson River were also restudied. If the new maps are approved, some older subdivisions on Glade Road north of State Highway 34 will be moved into the 100-year floodplain.

People who want to look at the proposed floodplain maps may go to the county engineering office on the third floor of the courthouse office building. To have someone explain the maps, they should call Woodward at 498-5705 for an appointment.