Dam owners are responsible for safe design, operation, and maintenance of a dam.  They are responsible to operate, maintain, and regularly inspect a dam so that it does not constitute a danger to human life or property.  The owners of high or significant hazard dams are required to develop and maintain effective Emergency Action Plans and coordinate those plans with local officials.

The Dam Safety Section is responsible for the safety of nearly 260 nonfederal dams in Arizona.  We perform safety inspections of high hazard dams every year, every three years for significant hazard dams, and every five years for low and very low hazard dams.  The dam owner is charged an inspection fee as prescribed in A.A.C. R12-13-151(12).  During inspections we sometimes identify “safety deficiencies” at operating dams and require owners to implement corrective actions.  A “safety deficiency” refers to a condition at a dam that impairs the safe operation of the dam.

Lists of Dams
AllJurisdictional Dams
Identified_Safety_Deficiencies Deficiencies
Jan2008statusofunsafedamsinarizona Unsafe

Maps showing the locations of all Arizona dams may be viewed at
http://phxsrv4.afws.org/cgi-bin/beta/main.cgi

Dam Repair Case Studies
Reconstructing River Reservoir No. 3 - From Emergency Action to Breach to Safe Operation in 21 Months

Applications to Construct, Reconstruct, Enlarge, Alter, Repair, Breach, or Remove a Dam

A.R.S. §45-1203 requires written approval of a formal application prior to construction of a new dam, or the enlargement, repair, alteration or removal of an existing dam.  The application process must comply with A.A.C. R12-15-1207, which also defines specific situations that do not require an application.  Application filing fees vary based on project cost and are prescribed in A.A.C. R12-13-151(12).

An applicant must contact the Dam Safety Section to schedule pre-application conferences.  These conferences are to discuss ADWR requirements and resolve issues essential to the design of the dam while the dam is in preliminary stages.  An applicant may submit preliminary design calculations for review and comment.  The Dam Safety Section will comment as soon as practicable, depending on the size of the submittal and current workload. 

Following receipt of an application, the Dam Safety Section performs an administrative review as prescribed in A.A.C. R12-15-401(1) and notifies the applicant whether the application is complete.  If the application is not complete, a list of additional required information is sent to the application.  After finding the application to be complete, the Dam Safety Section performs a substantive review as prescribed in A.A.C. R12-15-401(3).  If during this review period if it is determined that defects in the application exist that would impact human life and property, a written notice of the defects is sent to the applicant.

ADWR Guidelines and Forms

The following guidelines and forms are provided in order to assist dam owners and their engineers in performing work that meet Dam Safety Section technical requirements.

Forms

Emergency Action Plan Template

PMF Hydrology and Routing Guidelines
Flood Protection for Dams with no Spillways
Requirements for Emergency Action Plans

Technical References for Dam Design, Construction, Repair and Analysis

The Dam Safety Section requires dam engineering analyses and designs be based on appropriate standardized state-of-the-practice methods. The list below is examples of standard references on dam design, construction, repair, and analysis that the Dam Safety Section routinely accepts.  A much more extensive list of references is provided in the Instructions for Filing an Application document.

USBR 1981 Freeboard Criteria and Guidelines

USBR 1998 Prediction of Embankment Dam Breach Parameters

FEMA 1998 Selecting and Accommodating Inflow Design Floods for Dams

NOAA 1984 Hydrometerological Report No 49

USBR 1996 Concrete Repair Manual

NRCS 1994 Gradation Design of Sand and Gravel Filters

Links to Dam Engineering References Available for Download

Federal Energy Regulatory Commission Engineering Guidelines
http://www.ferc.gov/industries/hydropower/safety/guidelines/eng-guide.asp

U.S. Army Corps of Engineers Engineering Manuals
http://www.usace.army.mil/inet/usace-docs/eng-manuals/em.htm

U.S. Army Corps of Engineers Technical Letters
http://www.usace.army.mil/inet/usace-docs/eng-tech-ltrs/etl-cw.html

Natural Resources Conservation Service Engineering
http://www.nrcs.usda.gov/technical/ENG/

U.S. Bureau of Reclamation Earth and Geology Manuals
http://www.usbr.gov/library/BRreclamation.html

Dam Safety Related Internet Sites

Arizona Division of Emergency Management
http://www.dem.state.az.us/

Association of State Dam Safety Officials (ASDSO)
http://www.damsafety.org/

Federal Emergency Management Agency National Dam Safety Program (NDSP)
http://www.fema.gov/plan/prevent/damfailure/index.shtm

National Performance of Dams Program (NPDP)
http://npdp.stanford.edu/

National Inventory of Dams (USCOE)
http://crunch.tec.army.mil/nid/webpages/nid.cfm

United States Society on Dams (USSD)
http://www.ussdams.org/

ENGINEERING TECHNICAL SUPPORT SECTION

The Engineering Technical Support Section’s responsibility is to assist Agency Divisions by collecting water supply and water use data to aid in effective management of the resources.  This section provides support in planning studies, hydrologic analyses, dam safety inspections of registered and unregistered dam, flood mitigation, surface water rights, and adjudication activities.  We also offer support in the preparation of required technical reports for other Sections within the Agency.  Authority for these activities can be found in ARS § 45-105, 45-112, 45-141, 45-151 et seq., 45-171 et seq., 45-181 et seq, 45-251 et seq, 45-271 et seq., and 45-1201 et seq.

The mission of the Engineering Technical Support Section is:

To assist in reducing the likelihood of catastrophic failure of jurisdictional dams minimizing the risk for loss of life and property damage, ensuring a long-term, sufficient, and secure water supply for the State by investigating and support managing the rights and interests of the State’s water resources for the citizens of Arizona.

FLOOD MITIGATION SECTION

The Flood Mitigation Section, consisting of the Floodplain Management Unit and the Flood Warning Unit, is responsible for assisting communities that participate in the National Flood Insurance Program (NFIP).  The section administers the Community Assistance Program; assists in delineation of floodplains and developing flood control projects; sets State Standards for floodplain management; and coordinates the planning, design, and construction of flood warning systems.  The section also works with local, state, and federal entities during times of flood emergencies.  Statutory authorities for the activities of the section are found in A.R.S. §§ 45-105, 45-1441 et seq., 45-1471 et seq., 45-1491, 45-1501 et seq., and 48-3601 et seq.

The mission of the Flood Mitigation Section is:

To reduce the loss of lives, property, and water resources in Arizona by providing appropriate flood information to the National Weather Service and local entities, and by facilitating appropriate development and mitigating the impact of inappropriate development within floodplains through structural and nonstructural flood control planning assistance.

Floodplain Management Unit

ADWR is the state coordinating agency for the NFIP.  The Floodplain Management Unit fulfills this function and provides technical assistance to those communities that participate in the program.  The Unit also has the responsibility of developing State Standards for floodplain delineation and mapping and assists in flood hazard mitigation planning.  When funding is available, the unit allocates State monies to county flood control districts and communities to study, design, and implement structural and nonstructural flood control projects.

In September of 1977, Arizona Governor Raul Castro signed Executive Order No. 77-6, thereby requiring all state agencies to comply with the National Flood Insurance Program, National Flood Insurance Act of 1968, and the Flood Disaster Protection Act of 1973.

In 1980, the Arizona State Legislature designated the newly created Arizona Department of Water Resources as the state coordinating agency for the National Flood Insurance Program (NFIP).

Authority

Several key components in statute give authority to the director of ADWR to do the following:

• Act as the official representative for the state with regard to floodplain activities, including investigation, study, survey, and compilation of data, and to keep the public informed;
   
• Assist in the establishment of floodplain boundaries;
   
• Assist the flood control districts with topographic mapping if sufficient funds are available;
   
• Contract with private businesses or other government agencies for floodplain management activities; and
   
• Act as the state coordinator for assistance to local jurisdictions in the National Flood Insurance Program; to coordinate with the Army Corps of Engineers flood management services; and to coordinate research among federal, state, and local agencies, including making recommendations.

Community Assistance Program

ADWR’s floodplain management program is funded primarily by FEMA’s Community Assistance Program (CAP).  One of the main objectives of CAP is to assure that jurisdictions adopt and enforce their local floodplain management ordinance in accordance with regulations of the National Flood Insurance Program (NFIP) and the Arizona Revised Statutes (A.R.S.).  ADWR has developed several Floodplain Management Model Ordinances that meet state and federal requirements. 

The first Floodplain Management Model Ordinance (Word version, PDF version) is for a non-Colorado River community that manages its own floodprone areas. 
 

The second Floodplain Management Model Ordinance is for a non-Colorado River community that depends on a county to assist in managing floodprone areas. 
 

The third Floodplain Management Model Ordinance (Word version, PDF version) is for a Colorado River community that manages its own floodprone areas 
 

The fourth Floodplain Management Model Ordinance is for a Colorado River community that depends on a county to assist in managing floodprone areas.

• Workshops:  Floodplain management workshops provide updated information and training for community officials and others interested in floodplain management.  Three workshops are presented throughout the State each year and are advertised on the webpage.  Topics include the FEMA Elevation Certificate, Duties of the Local Floodplain Administrator, and Substantial Improvement and Substantial Damage of Structures located in floodplains.
   
• Community Assistance Visits (CAV):  There are 99 NFIP participating communities in Arizona.  It is the goal of ADWR to visit 20% of the communities each year to provide updates on state and federal floodplain management program changes, provide technical and programmatic assistance and verify that development in floodprone areas is compliant with local floodplain management regulations.  In cooperation with FEMA, each year the Unit develops a five-year CAV schedule for NFIP participating communities.
   
• Technical Assistance:  Assistance relating to the NFIP and related Arizona Revised Statutes is provided to community officials and the citizens of Arizona.  The Handbook for Arizona Communities on Floodplain Management and the NFIP was prepared by ADWR in 2000.  This Handbook is a reference and a guide for Arizona communities participating in the NFIP.

Flood Map Modernization

The Federal Emergency Management Agency (FEMA) has been creating flood hazard maps for National Flood Insurance Program (NFIP) communities since the 1970s.  These maps, known as Flood Insurance Rate Maps (FIRMs), show designated flood zones and physical features such as major highways, secondary roads, railroads, lakes, rivers, streams and sheet flow areas.

Community officials use the FIRMs to administer floodplain management regulations and mitigate flood damage.  Lending institutions use them to locate properties and buildings and determine whether flood insurance is required when making loans or providing grants for the purchase or construction of buildings.  Federal agencies use the FIRMs to target areas for mitigation projects.  It is important that these flood maps be accurate, reliable, and easily accessible.

Many of the FIRMS for Arizona communities are outdated because they no longer accurately reflect jurisdictional boundaries, street names, and physical features.  FEMA has instituted the national Map Modernization Management Support (MMMS) program to update and modernize the flood maps.  ADWR's Floodplain Management Unit is collaborating with FEMA, county flood control districts and local communities across the state during this process.

Levee certification issues have recently affected the production of the new Digital Flood Insurance Rate Maps (DFIRMs).  This delay is due to nationwide concerns about the safety of levees that provide flood protection.  To learn more about the levee issue and how it will affect the DFIRMs, please visit FEMA’s website: www.fema.gov/plan/prevent/fhm/lv_intro.shtm

Upcoming Training Opportunities

Links:

Federal Emergency Management Agency
http://www.fema.gov

Association of State Floodplain Managers
http://www.floods.org

Arizona Floodplain Management Association
http://www.azfma.org

State Standards

The ADWR State Standards Work Group was formed in 1990 to develop standards and provide technical assistance to promote consistent responsible floodplain management and watercourse use on a statewide basis.  These standards are mandated by state law, as stated in A.R.S. § 48-3605(A), which states, “The director of water resources shall develop and adopt criteria for establishing the one-hundred year flood and delineating floodplains.”

To accomplish this goal, the State Standards Work Group is developing a comprehensive set of publications and training resources that are used for consistent floodplain management and watercourse use through:

• Utilizing input and expertise from local, state, federal and private entities;
• Seeking sufficient funding needed to implement our mission successfully; and
• Providing training opportunities on the proper use of State Standards and related issues in cooperation with the educational community.

The membership of the State Standards Work Group consists of representatives of the following agencies and organizations who donate their time and resources to support the goals of the Work Group:

• Arizona Department of Water Resources, Flood Mitigation Section;
• 2 Urban Counties;
• 2 Rural Counties; and
• Arizona Floodplain Management Association (AFMA) Technical Committee

Funding for the State Standards program is obtained by voluntary donations from agencies and others who benefit from the State Standards.

The following table describes all current State Standards:

The State Standards Work Group has and continues to develop training programs on the proper use of the Standards.  Training is normally provided at various locations around the state at no (or very low) cost to the participants.  Training programs developed to date include the following:

SS2-96  1 of 3  Floodplain and Floodway Delineation in Riverine Environments
SS2-96  2 of 3  Floodplain and Floodway Delineation in Riverine Environments
SS2-96  3 of 3  Floodplain and Floodway Delineation in Riverine Environments

SS8-99  Stormwater Detention/Retention

Floodplain Issues in Transportation Design

Section I	Introduction
Section II	Overview of Regulations
Section III	Overview of ADWR/ADEM Roles
Section IV	Overview of State Standards
Section V	Flood Hydrology and Floodplain Hydraulics
Quiz 1	Quiz 1
Section VI	River Engineering and Geomorphology
Quiz 2	Quiz 2
Section VII	Effects of Transportation Structures on Fluvial Systems
Section VIII	Overview of Design Guidelines
Quiz 3	Quiz 3
Section IX	Design Process
Section X	Illustrated Examples

Related Technical Issues

Related Technical References (9.5MB)

Design Manual for Engineering Analysis of Fluvial Systems

Current State Standards Projects

Update Coming Soon.

Upcoming Training Opportunities

Training Course on State Standard 9-02: Floodplain Hydraulic Modeling

When: December 6, 2007
Where: Casa Grande
Time: 8:00a - 5:00p

Registration information can be found at www.azltap.org

FLOOD WARNING UNIT

The Flood Warning Unit is active in coordinating the combined efforts of multiple entities engaged in warning the public of potential floods.  Entities include federal agencies such as the National Weather Service (NWS), the United States Geological Survey (USGS), the United States Army Corp of Engineers (USACE), the Natural Resources Conservation Service (NRCS), and the Bureau of Reclamation (BOR).  At the state level, there is an open line of communication with the Arizona Division of Emergency Management during times of flood assessment.  At the local level, the Flood Warning Unit works with county flood control districts and the Salt River Project to facilitate the sharing of data critical to evaluating potential threats from flooding.

In 1979, the Arizona Legislature authorized funds to create the Arizona Flood Warning Office. (The Department of Water Resources originated the following year, in June of 1980.)  Monies from the Flood Warning fund were largely used to support the Arizona offices of the US Geological Survey (USGS) in maintaining their stream flow gauges, and the National Weather Service (NWS) in improving flood prediction.  ADWR’s role expanded in 1994 when the legislature adopted Article 6, Flood Warning Systems, §45-1501 to 45-1506.   This action was in response to heavy flooding in 1993, during which time it became apparent that the state could benefit greatly from improved communication among government entities.

The Flood Warning statutes vested the director of ADWR with the authority to coordinate with the federal government, state agencies, and local entities such as county flood control districts to establish a statewide Flood Warning System.  ADWR may use Flood Warning funds to enter into intergovernmental agreements (IGA’s) with other entities as part of a cost-share contract for additional equipment.  Typically, the IGA stipulates the local entity will become owners of, and must maintain, the equipment.  ADWR staff may provide technical assistance as needed.  ADWR continues to provide financial support to the USGS on an annual basis for 35 of their 195 stream flow gauges across the State.  USGS employs satellite and radio telemetry to transfer stream flow data via radio signal to their offices, where a computer program translates raw data into stream height.  Data is transferred at 15 to 60 minute intervals, and appears on their website within one to four hours after transmittal.  USGS data in Arizona can be viewed at http://waterdata.usgs.gov/az/nwis/rt.

Since time is of the essence when faced with the prospect of a flood, ADWR participates in the statewide network of ALERT technology, developed by the NWS.  ALERT is an acronym for Automated Local Evaluation in Real Time. The phrase “real time” refers to the fact that data from a rain, stream, or weather gauge may be received within minutes after a measurement is automatically stored and transmitted.

Gauges have been placed at strategic locations around the State.  Typical sites for a gauge include washes, dams, low lying streets, and areas of recent fire where increased runoff and debris flows can create an even greater hazard.

ALERT technology relies on a radio signal sent automatically from a gauge transmitter, which is housed in an aluminum standpipe.  An enclosed tipping bucket rests atop the standpipe and measures precipitation by “tipping” back and forth with every 1 mm (0.4 inches) of rainfall.  Stream flow is measured by placing a highly sensitive device in the streambed, anchoring it with steel or PVC conduit, and running a cable into the standpipe.  Power is generated to the transmitter with a 12-volt battery, which is recharged daily by a solar panel mounted to the top of the antenna mast on the standpipe.

The transmitter can be programmed to send data at regularly scheduled intervals, such as every 15 minutes, or at a specified incremental change.  Most tipping buckets record every 1 mm (0.04 inches) of rainfall. Stream gauges are usually programmed to initiate a data transmission for every 0.05 foot of change in stream level, but can be programmed to transmit changes as small as 0.01 foot.

Gauge radio transmissions work by a method known as “line-of-site”.  The radio signal may be received directly by a base station antenna, or, if the station is too far away, by a mountain top “repeater” antenna. This antenna transmits the data along to the next line-of-site repeater antenna, if necessary.

The final destination of the data is a base station.  ADWR, ADEM, NWS, and many Arizona counties have a base station to receive transmitted data. The base station is equipped with a receiver, decoder, computer, and specialized software that translates the radio signal into a meaningful value.  Usually it takes just a few minutes for the base station to receive the signal from a gauge, but this varies with distance and the number of repeaters data from a particular gauge must pass through.  At ADWR’s base station, all of the state’s ALERT gauges are received.  For a complete list of all gauges, see the report ALERT Stations Received at ADWR’s Base Station.   Stream gauges are referred to as “stage” in that report.

Rainfall and stream flow are the two most common gauges used for Flood Warning, but some sites are equipped with additional sensors for measuring temperature, relative humidity, dew point, barometric pressure, wind speed and wind direction.  These “weather stations” are scattered across the state and may provide, for example, useful data for predicting the onset of the monsoon season, or for indicating wind direction in the case of a wildfire. Recently, sensors to indicate ice on roadways were installed in a few test locales.
Though still in the planning stage, the function of ALERT stations may soon be expanded to serve a role in the determination of drought conditions.

Most of the State’s active gauges can be viewed on a web page maintained by SRP through an IGA with ADWR.  This website is under constant development and enhancement and, while there are some “bugs” that still need to be worked out, the expectation is that one day soon it will be a highly useful tool for the public.

A Word of Caution:  FLOOD WATCHES AND FLOOD WARNINGS ISSUED BY THE NATIONAL WEATHER SERVICE SHOULD BE YOUR PRIMARY SOURCE IN ASSESSING FLOOD DANGER – NOT THE WEBSITE. DO NOT RELY ON THE WEBSITE TO MAKE CRUCIAL DECISIONS REGARDING YOUR SAFETY.  Data may not be quality checked and should be considered provisional.  While the responsible party for each county or flood control district attempts to perform “clean-up” of the data on a daily basis, unverified data does make its way onto the web.

http://phxsrv4.afws.org/cgi-bin/beta/main.cgi

RELATED LINKS

The National Weather Service (NWS) issues hydrologic and meteorologic (hydromet, for short) forecasts, watches and warnings.  Only the NWS can issue official Flood Watches and Flood Warnings to the public.  Offices with responsibility in Arizona are in Phoenix, Tucson, and Flagstaff, as well as Las Vegas, Nevada, and Salt Lake City, Utah. NWS offices are staffed 24 hours a day, seven days a week.  They rely on weather information from a number of different sources, including ALERT data.

National Weather Service - Phoenix
http://www.wrh.noaa.gov/psr/

National Weather Service - Flagstaff
http://www.wrh.noaa.gov/fgz/

National Weather Service - Tucson
http://www.wrh.noaa.gov/twc/

National Weather Service - Las Vegas
http://www.wrh.noaa.gov/vef/

The following counties maintain active ALERT data on the web:

Flood Control District of Maricopa County
http://www.fcd.maricopa.gov/
Choose “Programs and Services/Flood Warning and Data Collection”

Mohave County Flood Control District:
http://weather.co.mohave.az.us/perl/DWReports.pl

Pima County Regional Flood Control District
http://rfcd.pima.gov/alertsys/

Yavapai County Flood Control District
http://www.co.yavapai.az.us/departments/Dev/DevHome.asp

Related Links:

ALERT Country - wide
http://www.alertsystems.org 

Arizona Geological Survey
http://www.azgs.state.az.us/flood_links.htm

National Oceanic and Atmospheric Administration
http://www.ncdc.noaa.gov/oa/ncdc.html