New Earth Fissure Map for Maricopa County

The Arizona Geological Survey has just realeased a new earth fissure map for Maricopa County. This map is combination of the study area maps that cover parts of the county, so it's not really anything new, just a new (and perhaps more convinient) way of presenting the info.

With the new release, they got a little press from CBS Channel 5 in Phoenix.

New Fissure Maps and Subsidence Workshop

The AZGS has released new earth fissure study area maps. New earth fissure maps showing confirmed and unconfirmed earth fissures for Harquahala, Maricopa County, and the Friendly Corners, Tator Hills and Signal Peak areas of Pinal County are complete. The 1:24,000 scale maps can be downloaded free at the Arizona Geological Survey’s (AZGS) Earth Fissure Center (http://azgs.az.gov/efmaps). For interactive viewing and custom map-making at up to 1:12,000 scale, visit the Arizona Department of Real Estate’s Earth Fissure Viewer at http://azmap.org/fissures.

Also of note is the Land Subsidence and Earth Fissure Workshop in August - the infromation below is from Brian Conway of ADWR:

I wanted to remind everyone again about the upcoming AHS Land Subsidence and Earth Fissure Workshop. I am still accepting abstracts and need at least three more talks to attempt to fill the full day workshop. I also want to remind you to register for the workshop whether you will be presenting or attending; either way you will have to pay for the workshop. I was also wondering if anyone would be interested on giving a presentation about the Arizona Land Subsidence Group. Here is the information about the workshop:

Arizona Hydrological Society

American Institute of Hydrology

2009 Annual Water Symposium

Land Subsidence and Earth Fissure Workshop

Sunday, August 30th, 8:30 am – 5:00 pm

Scottsdale, Arizona

Westin Kierland Resort and Spa

Abstracts should be 250 words or less and include title, authorship, and affiliations. Please include a brief biographical sketch of the primary author(s) and indicate that the abstract is for the Land Subsidence and Earth Fissure Workshop. Please submit abstracts no later than July 30th.

Abstracts must be submitted electronically to: hydrosymposium@a6consultants.com

Please copy Brian Conway (Workshop Moderator) on the email for the abstract submittal: bdconway@azwater.gov

If you have questions about the workshop, please contact:

Brian Conway
Arizona Department of Water Resources
602.771.1517
bdconway@azwater.gov

Surficial Geologic and Flood Hazard Assessment of Rainbow Valley

Announcement From the AZGS:

The Arizona Geological Survey’s (AZGS) newest map product, "Surficial Geologic Map and Flood Hazard Assessment, Rainbow Valley, Maricopa County, Arizona", DGM – 71, displays the surface geology of Rainbow Valley on three map sheets at 1:24,000 map-scale; the three sheets encompass portions of 12 USGS 7.5 minute quadrangles.

The accompanying 11-page report includes a _Flood Hazard Assessment_ that pigeonholes map units into high, intermediate, or low flood hazard areas. The three flood hazard areas encompass more than 250 sq. miles of Rainbow Valley and environs: Flood Hazard High (76.29 sq. miles), Intermediate (129.76 sq. miles), and Low (48.25 sq. miles).

Within flood area categories, e.g., Flood Hazard High, units are arranged in order of decreasing frequency of flooding. For example, Qycr – Modern channels of Waterman Wash, has the highest flood frequency of the seven geologic units in the Flood Hazard High zone; Qyaf – Potentially active alluvial fans, has the lowest flood frequency in that same category.

This first flood hazard assessment will provide land-use planners of Maricopa County with a blueprint for directing future development in Rainbow Valley.

Rainbow Valley is a checkerboard of agricultural fields drained by Waterman Wash, which debouches into the Gila River to the north. AZGS mapping shows the valley floor and adjacent alluvial fans comprise a complex of fluvial sediments including channel and sheetflow deposits, terrace and bar deposits, alluvial fans, and sparse eolian sands, ranging in age from modern, through the Holocene or late Pleistocene, to early Quaternary or late Tertiary.

AZGS geologists Philip Pearthree, Ann Youberg, and Todd Shipman co-authored the work. Funding was provided by the Flood Control District of Maricopa County.

DGM-71, maps and report, are available on CD-ROM at the State Map & Bookstore, 416 W. Congress, Ste#100, Tucson, AZ, 85701, for $15.00.