FLOOD00767

• County: Jefferson
• County: Park
• Community: Buffalo Creek
• Title: Flood Mitigation and Flood Hazard Awareness for Residents of Buffalo Creek Colorado
• Date: 4/1/1997
• Prepared For: Jefferson County
• Floodplain - Doc Type: Flood Mitigation/Flood Warning/Watershed Restoration

. Recovery of native trees

· Recovery of humus layer (organic layer at soil surface)

The effects of an intense fire on the watershed's soil structure and hydrology can be significant.
The following key points about the effects of fire on soil and hydrology were extracted from U.S.
Forest Service publications.

· For arid areas of the U.S., vegetative regrowth after a severe burning can be very slow.
· Coarse textured soils are more likely to become highly water repellent than fine clay soils.
· Lodgepole and Ponderosa Pine forests have displayed high water repellency after burning.
· Soil formed from granitic parent material is sensitive to erosion. The erosion rate is a
function of the burn intensity.
· For recently burned watersheds, peak streamflows have been reported to be 2 to 60 times
greater than normal after a heavy rain.

Unfortunately, the Buffalo Creek area fits all of the above categories. Strategic planning and
mitigation can help to reduce the adverse affects caused by the fire. Previous research suggests that
the complete break -up of the hydrophobic soils can occur naturally as soon as I to 2 years after the
fire. The return of certain grasses and forbs should occur fairly rapidly as well. It will likely take a
much longer time for larger trees and shrubs to develop in the burned watershed. It is likely that
flash flooding could be a high risk over the next several years, and could then be a moderate risk for
many years thereafter. After the Black Tiger Run fire in Boulder County, the Bureau of
Reclamation obseryed that sediment production and runoff were most significant immediately
following the fire. By the next summer season, sediment production had decreased significantly.

D. NATIONAL WEATHER SERVICE RAIN GAGES
Thirteen residents in the Buffalo Creek area have been provided with National Weather Service
(NWS) rain gages. These gages are manual, non-recording instruments that are intended to
collect precipitation for use in reporting purposes. The residents with the gages have been given
the responsibility of placing, maintaining, monitoring, and operating them. Specific instructions
from the NWS were distributed to the residents who received the gages. Rainfall amounts should
be recorded and reported to the NWS during and after each storm event. The 24-hour NWS
reporting number is [phone]. In addition, residents should report rain levels to Grant
Macdonald at [phone] for the purpose of summarizing precipitation totals for each storm
and for each month during the flood season. The names, addresses, and phone numbers for the
locations of the rain gages is presented in Table I. The gage locations are presented graphically
on the map that follows Table I.

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