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Research about Maricopa County, Arizona

Source-linked reports with geographic coverage including Maricopa County, Arizona.

18 recordsLinked to original sources
USGS2018

Chlamydia psittaci in feral Rosy-faced Lovebirds (Agapornis roseicollis) and other backyard birds in Maricopa County, Arizona

In 2013, a mortality event of nonnative, feral Rosy-faced Lovebirds ( Agapornis roseicollis ) in residential backyards in Maricopa County, Arizona, US was attributed to infection with Chlamydia psittaci . In June 2014, additional mortality occurred in the same region. Accordingly, in August 2014 we sampled live lovebirds and sympatric bird species visiting backyard bird feeders to determine the prevalence of DNA and the seroprevalence of antibodies to C. psittaci using real-time PCR-based testing and elementary body agglutination, respectively. Chlamydia psittaci DNA was present in conjunctival-choanal or cloacal swabs in 93% (43/46) of lovebirds and 10% (14/142) of sympatric birds. Antibodies to C. psittaci were detected in 76% (31/41) of lovebirds and 7% (7/102) of sympatric birds. Among the sympatric birds, Rock Doves ( Columba livia ) had the highest prevalence of C. psittaci DNA (75%; 6/8) and seroprevalence (25%; 2/8). Psittacine circovirus 1 DNA was also identified, using real-time PCR-based testing, from the same swab samples in 69% (11/16) of species sampled, with a prevalence of 80% (37/46) in lovebirds and 27% (38/142) in sympatric species. The presence of either Rosy-faced Lovebirds or Rock Doves at residential bird feeders may be cause for concern for epizootic and zoonotic transmission of C. psittaci in this region.

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USGS2015

Continuous slope-area discharge records in Maricopa County, Arizona, 2004–2012

Continuous slope-area (CSA) streamgages have been developed and implemented by the U.S. Geological Survey (USGS) to enable the recording of discharge hydrographs in areas where direct discharge measurements cannot be made. The flashy nature of streamflow in parts of the arid Southwest and remote location of many sites make discharge measurements difficult or impossible to obtain. Consequently, available discharge measurements may be insufficient to develop accurate rating curves, which relate discharge to continuously recorded stage measured at standard streamgages. Nine CSA streamgages have been installed in Maricopa County, Arizona, since 2004 in cooperation with the Flood Control District of Maricopa County. This report presents the data and analysis of computed discharges from those streamgages, along with descriptions of the streamgage site and stream properties. Analyses of sources of errors and the impact stage data errors have on calculated discharge time series are considered, along with issues in data reduction. Steeper, longer stream reaches are generally less sensitive to measurement error. Other issues considered are pressure transducer drawdown, capture of flood peaks with discrete stage data, selection of stage record for development of rating curves, and minimum stages for the calculation of discharge.

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USGS2002

Determination of channel change for selected streams, Maricopa County, Arizona

In Maricopa County, Arizona, 10 sites on seven streams were studied to determine the lateral and vertical change of the channel. Channel change was studied over time scales ranging from individual floods to decades using cross-section surveys, discharge measurements, changes in the point of zero flow, and repeat photography. All of the channels showed some change in cross-section area or hydraulic radius over the time scales studied, but the direction and mag-nitude of change varied considerably from one flow, or series of flows, to another. The documentation of cross-section geometry for streams in Maricopa County for long-term monitoring was begun in this study.

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USGS2001

Potential errors associated with stage-discharge relations for selected streamflow-gaging stations, Maricopa County, Arizona

Potential errors were derived for individual discharge measurements and stage-discharge relations for 17 streamflow-gaging stations in Maricopa County. Information presented primarily consists of stage and discharge data that were used to develop the stage-discharge relations that were in effect for water year 1998. Accuracy of the discharge measurements directly relate to accuracy of the stage-discharge relation developed for each site. Stage-discharge relations generally are developed using direct measurements of stage and discharge, indirect measurements of peak discharge, and theoretical weir and culvert computations. Accuracy of current-meter measurements of discharge (direct measurements) depends on factors such as the number of subsections in the measurement, stability of the channel, changes in flow conditions, and accuracy of the equipment. Accuracy of indirect measurements of peak discharge is determined by the accuracy of discharge coefficients and flow type selected for the computations. The accuracy of indirect peak-discharge computations generally is less than the accuracy associated with current-meter measurements. Current-meter measurements, indirect measurements of discharge, weir and culvert computations, and step-backwater computations are graphically represented on plots of the stage-discharge relations. Potential errors associated with the discharge measurements at selected sites are depicted as error bars on the plots. Potential errors derived for discharge measurements at 17 sites range from 5 to 25 percent. Errors generally are greater for measurements of large flows in channels having unstable controls using indirect methods.

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USGS2001

Statistical summary of selected physical, chemical, and toxicity characteristics and estimates of annual constituent loads in urban stormwater, Maricopa County, Arizona

Stormwater and streamflow in Maricopa County were monitored to (1) describe the physical, chemical, and toxicity characteristics of stormwater from areas having different land uses, (2) describe the physical, chemical, and toxicity characteristics of streamflow from areas that receive urban stormwater, and (3) estimate constituent loads in stormwater. Urban stormwater and streamflow had similar ranges in most constituent concentrations. The mean concentration of dissolved solids in urban stormwater was lower than in streamflow from the Salt River and Indian Bend Wash. Urban stormwater, however, had a greater chemical oxygen demand and higher concentrations of most nutrients. Mean seasonal loads and mean annual loads of 11 constituents and volumes of runoff were estimated for municipalities in the metropolitan Phoenix area, Arizona, by adjusting regional regression equations of loads. This adjustment procedure uses the original regional regression equation and additional explanatory variables that were not included in the original equation. The adjusted equations had standard errors that ranged from 161 to 196 percent. The large standard errors of the prediction result from the large variability of the constituent concentration data used in the regression analysis. Adjustment procedures produced unsatisfactory results for nine of the regressions?suspended solids, dissolved solids, total phosphorus, dissolved phosphorus, total recoverable cadmium, total recoverable copper, total recoverable lead, total recoverable zinc, and storm runoff. These equations had no consistent direction of bias and no other additional explanatory variables correlated with the observed loads. A stepwise-multiple regression or a three-variable regression (total storm rainfall, drainage area, and impervious area) and local data were used to develop local regression equations for these nine constituents. These equations had standard errors from 15 to 183 percent.

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USGS2000

Hydrogeology, water quality, and stormwater-sediment chemistry of the Grande Wash area, Fort McDowell Indian Reservation, Maricopa County, Arizona

Grande Wash is a tributary of the Verde River and drains an area of 13 square miles within the McDowell Mountains and the Town of Fountain Hills in Central Arizona. The wash enters the Fort McDowell Indian Reservation at the eastern boundary of Fountain Hills and is incised in coarse-grained alluvium that is contiguous with the alluvial aquifer along the Verde River. The aquifer is used by the Fort McDowell Indian Community and the City of Phoenix for municipal water supplies. Episodic flows in Grande Wash, in response to storms, carry potentially hazardous runoff from Fountain Hills onto the reservation. Additional potential hazards to ground water include contamination from a wastewater-treatment plant located less than 1 mile upstream from the reservation boundary, and from a landfill and a cement-processing plant immediately adjacent to the main channel of the wash. Coarse-grained deposits in Grande Wash also include recent stream-channel deposits, soil backfill, landfill material, and the upper coarse-grained layer of basin-fill sediments. Surface-geophysical surveys and drilling indicated that the coarse-grained deposits are less than 60-feet thick along the wash and in adjacent areas within the reservation, and are underlain by a thick clay and silt unit, the base of which is below the bottom of the deepest monitor well (317 feet below land surface). The coarse-grained deposits form the alluvial aquifer beneath Grande Wash. Ground water in the alluvial aquifer beneath the wash is shallow and mounded above a less permeable clay and silt unit. Depth to water in the aquifer ranges from 1 to 22 feet below land surface. Saturation of the coarse-grained deposits does not extend laterally for more than about 1,000 feet from the main channel of Grande Wash; the extent varies in response to recharge amounts. Flux of ground water through the alluvial aquifer beneath the wash is toward the Verde River and is estimated to be about 8,000 cubic feet per day (about 0.2 acre-feet per day). The flow rate is four orders of magnitude less than the flow rate in the Verde River. Vertical flux of ground water through the underlying clay and silt unit is estimated to be 7,000 cubic feet per day (0.17 acre-feet per day). The volume of ground water in storage in the alluvial aquifer beneath Grande Wash is estimated to be about 5.6 million cubic feet (129 acre-feet). Concentrations of dissolved inorganic constituents in ground water and surface water are high relative to concentrations found in the regional aquifer in surrounding areas and are indicative of salts that can be expected to be mobilized by runoff in the drainage area. Concentrations of nitrate, chloride, and sulfate are near U.S. Environmental Protection Agency Primary or Secondary Drinking-Water Regulations. Concentrations of arsenic, antimony, and strontium are below drinking-water standards but can be attributed to geologic deposits in and near the study area. Low concentrations of anthropogenic compounds, including chloroform and dichlorobromomethane, were detected. These compounds are disinfection by-products of chlorinated water. Eight pesticide compounds were detected in the surface water, and two pesticide compounds were detected in the ground water. Pesticide concentrations were below U.S. Environmental Protection Agency Maximum Contaminant Levels. Several other organic anthropogenic compounds that probably originated from commercial activities in the area were detected but at concentrations below laboratory calibration standards. Concentrations of trace metals in the stormwater sediment collected from the sediment retention basin in the lowest part of the wash were low and several were below the laboratory’s detection limits. Concentrations of most organic compounds in the stormwater sediment were below detection limits. Organic compounds present at concentrations above detection limits were p-cresol and two phthalate esters—bis (2-ethylhexyl) phthalate and dibutyl phthalate. P-cresol is used in pesticides or in disinfectants and deodorizers, and phthalate esters are commonly used in plastics, hydraulic fluid, and electric capacitors.

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USGS2000

Computed roughness coefficients for Skunk Creek above Interstate 17, Maricopa County, Arizona

In the winter of 1997-98, the U.S. Geological Survey, in cooperation with the Flood Control District of Maricopa County, made six verification measurements for Manning's roughness coefficients at Skunk Creek above Interstate 17. Data from four floodflows were recorded and analyzed, three of these flows occurred in February 1998 when Arizona received precipitation from the El Nino weather phenomenon. Discharges ranged from 187 to 760 cubic feet per second and resultant verified values for Manning's roughness coefficient, n, ranged from 0.056 to 0.039. Skunk Creek above Interstate 17 - an ephemeral wash within a flood-control structure - is overgrown with desert brush throughout the main channel and the presence of the vegetation has a significant effect on n values throughout the reach. The results of this study are verified roughness coefficients that can be transferred to similarly vegetated channels in Maricopa County and other arid and semiarid environments where roughness factors must be assessed for flood management or other purposes.

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USGS1995

Statistical summary of selected physical, chemical, and microbial characteristics, and estimates of constituent loads in urban stormwater, Maricopa County, Arizona

Stormwater and streamflow in the Phoenix, Arizona, area were monitored to determine the physical, chemical, and microbial characteristics of storm- water from areas having different land uses; to describe the characteristics of streamflow in a river that receives urban stormwater; and to estimate constituent loads in stormwater from unmonitored areas in Maricopa County, Arizona. Land use affects urban stormwater chemistry mostly because the percentage of impervious area controls the suspended-solids concentrations and varies with the type of land use. Urban activities also seem to concentrate cadmium, lead, and zinc in sediments. Urban stormwater had larger concentrations of chemical oxygen demand and biological oxygen demand, oil and grease, and higher counts of fecal bacteria than streamflow and could degrade the quality of the Salt River. Most regression equations for estimating constituent loads require three explanatory variables (total rainfall, drainage area, and per- centage of impervious area) and had standard errors that were from 65 to 266 percent. Localized areas that appear to contribute a large proportion of the constituent loads typically have 40 percent or more impervious area and are associated with industrial, commercial, and high-density residential land uses. The use of the mean value of the event-mean constituent concentrations measured in stormwater may be the best way of estimating constituent concentrations.

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USGS1995

Selected chemical characteristics and acute toxicity of urban stormwater, streamflow, and bed material, Maricopa County, Arizona

The chemistry and toxicity of urban stormwater, streamflow, and bed material in the Phoenix, Arizona, area were characterized to determine if urban stormwater could degrade the quality of streams. Toxic phases of stormwater (oil and grease, suspended solids, dissolved metals, and dissolved organics) were identified to aid water-quality managers minimize the sources of toxicants. Acute aquatic toxicity tests were done using the water flea Ceriodaphnia dubia and fathead minnows (Pimaphales promelas), and acute sediment toxicity tests were done using the amphipod Hyalella azteca. Statistical analyses also were used to determine the effect of urbanization on the quality of water and bed material and to identify toxic constituents. Statistical analyses indicated that urban stormwater could degrade the quality of streamflow with oil and grease, pesticides, dissolved trace metals, and ammonia, and that ammonia, lead, cadmium, and zinc are released by urban activities and accumulate in bed material. Ammonia may be from fertilizers, fecal matter, and other sources. Lead probably is from vehicles that use leaded gasoline. Cadmium and zinc could be from paniculate metal in oil, brake pads, and other sources. Samples of the initial runoff from urban drainage basins appeared to be more toxic than flowweighted composite samples, and stormwater was more harmful to fathead minnows than to Ceriodaphnia dubia. Streamflow samples from the Salt River were not toxic to either species, which indicates that urban stormwater could degrade the quality of the Salt River. The enhanced mortality rate of fathead minnows exposed to urban stormwater from most urban drainage basins indicated that the toxicants were more detrimental to fish than to insects and could be present in stormwater throughout the Phoenix area. The most toxic stormwater samples were collected from the drainage basins with residential and commercial land use, and the toxicity probably was due to surfactants and (or) other constituents leached from asphalt and resealant Results of toxicity identification evaluations indicated that the toxicity of stormwater mostly was due to organic constituents; dissolved zinc and copper also appeared to contribute to stormwater toxicity. Statistical comparisons of chemical data to toxicity data indicated that organophosphate pesticides were not the toxic constituents, and the toxicity generally was due to organic constituents that were not analyzed. The most toxic bed-material samples were collected from a drainage basin with undeveloped land use. In these bed-material samples, mortality rates were significantly higher than in samples from ephemeral channels. Comparisons between the toxicity of bed-material samples from undeveloped and urban drainage basins and between urban drainage basins and ephemeral channels showed no significant difference. In urban drainage basins, bed-material samples collected from areas where stormwater accumulates appeared to be more toxic than samples collected from areas where stormwater does not accumulate. For bed-material samples from the undeveloped drainage basin, mortality rates strongly correlated with recoverable concentrations of zinc and moderately correlated with recoverable concentrations of copper. The high mortality rate probably was due to naturally occurring trace metals. For bed-material samples from urban drainage basins, mortality rates significantly correlated with recoverable concentrations of cadmium and zinc, which resulted from urban activities. The bioavailability of trace metals in bed material appeared to be controlled by the adsorption properties of organic carbon, iron, and manganese. Organochlorine pesticides were detected in most bed-material samples; however, mortality rates were poorly correlated with pesticide concentrations.

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USGS1989

Hydrogeology of the western part of the Salt River Valley area, Maricopa County, Arizona

The Salt River Valley is a major population and agricultural center of more than 3,000 mi 2 in central Arizona (fig. 1). The western part of the Salt River Valley area (area of this report) covers about 1,500 mi 2 . The Phoenix metropolitan area with a population of more than 1.6 million in 1985 (Valley National Bank, 1987) is located within the valley. The watersheds of the Salt, Verde, and Agua Fria Rivers provide the valley with a reliable but limited surface-water supply that must be augmented with ground water even in years of plentiful rainfall. Large-scale ground-water withdrawals began in the Salt River Valley in the early part of the 20th century; between 1915 and 1983, the total estimated ground-water pumpage was 81 million acre-ft (U.S. Geological Survey, 1984). Because of the low average annual rainfall and high potential evapotranspiration, the principal sources of ground-water recharge are urban runoff, excess irrigation, canal seepage and surface-water flows during years of higher-than-normal rainfall. Withdrawals greatly exceed recharge and, in some area, ground-water levels have declines as much as 350 ft (Laney and other, 1978; Ross, 1978). In the study area, ground-water declines of more than 300 ft have occurred in Deer Valley and from Luke Air Force Base north to Beardsley. As a result, a large depression of the water table has developed west of Luke Air Force Base (fig. 2). Ground-water use has decreased in recent years because precipitation and surface-water supplies have been greater than normal. Increased precipitation also caused large quantities of runoff to be released into the normally dry Salt and Gila River channels. From February 1978 to June 1980, streamflow losses of at least 90,000 acre-ft occurred between Jointhead Dam near the east boundary of the study area and Gillespie Dam several miles southwest of the west edge of the study area (Mann and Rhone, 1983). Consequently, ground-water declines in a large part of the basin have slowed, and ground-water levels in some sarea have risen significantly. In many areas along the Salt River and northeast of the confluence of the Salt and Agua Fria River, ground-water levels rose more than 25 ft between 1978 and 1984 (Reeter and Remick, 1986).

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USGS1978

Maps showing ground-water conditions in the western part of the Salt River Valley area, Maricopa County, Arizona, 1977

In 1976 about 1.68 million acre-feet of ground water was pumped in the Salt River Valley. Since 1923, more than 73 million acre-feet has been withdrawn, which has resulted in a general decline in water levels. Water levels in the western part of the Salt River Valley area have declined as much as 350 feet. Information on the maps includes altitude of the water level, depth to water, change in water level (1923-77), and irrigated area. Long-term hydrographs of the water level in selected wells, a table of historical pumpage, and a brief discussion of the chemical quality of the ground water are included also.

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USGS1970

Winds over saltcedar

An analysis of hourly wind speeds above and within a stand of saltcedar near Buckeye, Arizona, reveals that in 90% of all observed cases, the wind profiles above the stand can be represented by the simple logarithmic equation: u z = u* k 1 n "> uz=u*k1n ( z z 0 ) "> zz0) where u z is the velocity at height z. The roughness length (z 0 ), (disregarding zero displacement), varies with a stability ratio similar to Richardson's number. The friction velocity, u* , depends on the wind speeds above the vegetation. Von Karman's constant, k, equals 0.41. Within the thickets there is considerable turbulence, and irregular wind inversions occur during daylight hours. The results are important for estimating water losses by evapotranspiration by either the energy-budget or the mass-transfer formulae.

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