A COMBINED STABLE AND RADIOISOTOPE STUDY OF THE SOURCES OF RECHARGE IN THE COACHELLA VALLEY AQUIFER SYSTEM, RIVERSIDE COUNTY, CALIFORNIA

In May 2012 in the Coachella valley, Riverside County, California, the decline of vines in table grape (Vitis vinifera) vineyards was observed. Foliar symptoms consisted of shoot blight with wilting and necrosis of leaves and drying and shriveling of berries. In some cases, the entire vine collapsed in the middle of the growing season (apoplexia). Wood cankers in the spurs, cordons, and trunks of affected vines were also present. The nine isolates recovered from the cankers were identified as Neoscytalidium dimidiatum (Penz.) Crous & Slippers based on morphological characteristics and DNA sequence comparisons. Two isolates were grown on potato dextrose agar (PDA) medium and a total of 50 conidia were measured per isolate. Conidia were ellipsoid to ovoid, with a truncate base and an acutely rounded apex, initially aseptate, becoming brown and two-celled at maturity, 7.2 ± 1.2 μm × 3.8 ± 0.4 μm. The rDNA internal transcribed spacer (ITS), and β-tubulin (BT) loci were amplified using primer pairs and methods previously described (4). A total of five isolates were sequenced. The DNA sequences of one N. dimidiatum grapevine isolate (UCR-Neo1) were deposited in the GenBank database (ITS, KC937066; BT, KC937067). Pathogenicity tests were performed by inoculating 12 grape cuttings cv. Thompson Seedless with isolate UCR-Neo1 and 12 control cuttings with sterile medium using a technique previously described (1). The experiment was repeated twice. After 20 weeks of incubation period in the greenhouse, the lesions length produced by N. dimidiatum averaged 13.5 mm and was significantly longer (P < 0.05) from the control (average 3 mm). N. dimidiatum was reisolated from all the inoculated plants and identified by colony morphology. The incidence of N. dimidiatum in table grape vineyards of the Coachella valley has been estimated at 15%, with nine vines infected out of 60 vines total. This pathogen has been identified in California in walnut nursery causing the death of trees due to the development of canker at the graft union (2). N. dimidiatum has also been identified as the causal agent of shoot blight, canker, and gummosis on citrus in Italy (3). The crop is also being grown in the Coachella valley and these findings warrant further investigation in order to determine the host range, distribution, and incidence of this pathogen in the area. References: (1) K. Baumgartner et al. Plant Dis. 97:912, 2013. (2) S. F. Chen et al. Plant Dis. 97:993, 2013. (3) G. Polizzi et al. Plant Dis 93:1215, 2009. (4) J. R. Urbez-Torres et al. Plant Dis. 92:519, 2008.

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The “Ancient Stone Fish Traps” of the Coachella Valley, Southern California

American Antiquity ◽

10.2307/275131 ◽

1945 ◽

Vol 10 (3) ◽

pp. 285-294 ◽

Cited By ~ 3

Author(s):

Adan E. Treganza

Keyword(s):

High Water ◽

Salton Sea ◽

Ancient Lake ◽

The West ◽

Coachella Valley ◽

Riverside County ◽

Fish Traps ◽

Small Stone ◽

Talus Slope ◽

Lake Cahuilla

A group of small stone enclosures, supposed by some to be of natural origin and by others to be the works of man, lies on a rocky travertine-encrtfsted talus slope at the base of the Santa Rosa Mountains on the west side of the Coachella Valley in Riverside County, California. These phenomena are known locally as the "Ancient Fish Traps." They occupy a series of rocky terraces some 90 feet below the maximum high-water shore line of Ancient Lake Cahuilla (called by some Blake Sea), whose basin is now partly occupied by the Salton Sea. The “traps” consist of 85 to 100 bowl-like depressions composed of a travertine-encrusted granite talus debris. They are arranged in three rows, each of which follows the exact contour of one of the old recessional terraces of the lake (Pl. XIX).

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Microbial contamination of drinking water from vending machines of Eastern Coachella Valley

Water Science & Technology Water Supply ◽

10.2166/ws.2020.372 ◽

2020 ◽

Author(s):

Thomas D. Hile ◽

Stephen G. Dunbar ◽

Ryan G. Sinclair

Keyword(s):

Drinking Water ◽

Environmental Protection Agency ◽

Tap Water ◽

Genetic Material ◽

Measured Temperature ◽

Salmonella Spp ◽

Total Coliforms ◽

Coachella Valley ◽

Riverside County ◽

Vending Machines

Abstract Drinking water quality from sources other than tap water is increasingly becoming a source of concern in many communities. Communities in the Eastern Coachella Valley (ECV), Riverside County, California, USA have raised concerns regarding bulk drinking water from water vending machines (WVMs) found in public vendors. To address concerns, we conducted microbiological contamination assessments of drinking water from WVMs in the ECV using heterotrophic plate counts (HPC), the presence of total coliforms using IDEXX technology, and real time PCR (qPCR). We also measured temperature, pH, electrical conductivity, and free chlorine concentration. Twenty-five WVMs were sampled by using positively charged NanoCeram® filters in the field. Results indicated 32% of WVMs had total coliforms, and 21% had HPC above Environmental Protection Agency (EPA) requirements. Through qPCR, we found 81% of WVMs had Salmonella spp, Listeria monocytogenes, and Campylobacter jejuni, 76% had Enterococcus faecalis, and 90% had Pseudomonas aeruginosa. Results indicated most WVM samples we collected contained genetic material of pathogenic microorganisms and therefore, did not meet EPA drinking water standards. There is an urgency to enforce WVM maintenance through drain flushing, spigot cleaning, rust removal, filter replacement, and limits to physico-chemical parameters.

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Mitigating Land Subsidence in the Coachella Valley, California, USA: An Emerging Success Story

Proceedings of the International Association of Hydrological Sciences ◽

10.5194/piahs-382-809-2020 ◽

2020 ◽

Vol 382 ◽

pp. 809-813

Author(s):

Michelle Sneed ◽

Justin T. Brandt

Keyword(s):

Land Subsidence ◽

Groundwater Level ◽

Water Levels ◽

Mitigation Measures ◽

Aquifer Recharge ◽

Domestic Water ◽

Aquifer System ◽

Groundwater Levels ◽

Coachella Valley ◽

Groundwater Overdraft

Abstract. Groundwater has been a major source of agricultural, municipal, and domestic water supply since the early 1920s in the Coachella Valley, California, USA. Land subsidence, resulting from aquifer-system compaction and groundwater-level declines, has been a concern of the Coachella Valley Water District (CVWD) since the mid-1990s. As a result, the CVWD has implemented several projects to address groundwater overdraft that fall under three categories – groundwater substitution, conservation, and managed aquifer-recharge (MAR). The implementation of three projects in particular – replacing groundwater extraction with surface water from the Colorado River and recycled water (Mid-Valley Pipeline project), reducing water usage by tiered-rate costs, and increasing groundwater recharge at the Thomas E. Levy Groundwater Replenishment Facility – are potentially linked to markedly improved groundwater levels and subsidence conditions, including in some of the historically most overdrafted areas in the southern Coachella Valley. Groundwater-level and subsidence monitoring have tracked the effect these projects have had on the aquifer system. Prior to about 2010, water levels persistently declined, and some had reached historically low levels by 2010. Since about 2010, however, groundwater levels have stabilized or partially recovered, and subsidence has stopped or slowed substantially almost everywhere it previously had been observed; uplift was observed in some areas. Furthermore, results of Interferometric Synthetic Aperture Radar analyses for 1995–2017 indicate that as much as about 0.6 m of subsidence occurred; nearly all of which occurred prior to 2010. Continued monitoring of water levels and subsidence is necessary to inform the CVWD about future mitigation measures. The water management strategies implemented by the CVWD can inform managers of other overdrafted and subsidence-prone basins as they seek solutions to reduce overdraft and subsidence.

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THE LIFE HISTORY AND BREEDING HABITS OF THE EYE GNAT, HIPPELATES PUSIO LOEW, IN THE COACHELLA VALLEY, RIVERSIDE COUNTY, CALIFORNIA

American Journal of Epidemiology ◽

10.1093/oxfordjournals.aje.a119444 ◽

1951 ◽

Vol 53 (2) ◽

pp. 164-177

Author(s):

ROBERT W. BURGESS

Keyword(s):

Life History ◽

Coachella Valley ◽

Riverside County

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Hydrogeological and isotopic study of the multi-aquifer system of the Sibari Plain (Calabria, Southern Italy)

Rendiconti online della Società Geologica Italiana ◽

10.3301/rol.2015.158 ◽

2016 ◽

Vol 39 ◽

pp. 134-137 ◽

Cited By ~ 1

Author(s):

Giovanni Vespasiano ◽

Carmine Apollaro ◽

Luigi Marini ◽

Rocco Dominici ◽

Giuseppe Cianflone ◽

...

Keyword(s):

Southern Italy ◽

Isotopic Study ◽

Aquifer System

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Using groundwater levels and Specific Yield to Estimate the Recharge, South of Erbil, Kurdistan Region, Iraq

Academic Journal of Nawroz University ◽

10.25007/ajnu.v7n4a289 ◽

2018 ◽

Vol 7 (4) ◽

pp. 191

Author(s):

Sherwan Sh. Qurtas

Keyword(s):

Unconfined Aquifer ◽

Middle Part ◽

Water Levels ◽

Specific Yield ◽

Aquifer System ◽

Groundwater Levels ◽

Monitoring Wells ◽

Water Table Fluctuation Method ◽

Recharge Estimation ◽

Fluctuation Method

Recharge estimation accurately is crucial to proper groundwater resource management, for the groundwater is dynamic and replenished natural resource. Usually recharge estimation depends on the; the water balance, water levels, and precipitation. This paper is studying the south-middle part of Erbil basin, with the majority of Quaternary sediments, the unconfined aquifer system is dominant, and the unsaturated zone is ranging from 15 to 50 meters, which groundwater levels response is moderate. The purpose of this study is quantification the natural recharge from precipitation. The water table fluctuation method is applied; using groundwater levels data of selected monitoring wells, neighboring meteorological station of the wells, and the specific yield of the aquifers. This method is widely used for its simplicity, scientific, realistic, and direct measurement. The accuracy depends on the how much the determination of specific yield is accurate, accuracy of the data, and the extrapolations of recession of groundwater levels curves of no rain periods. The normal annual precipitation there is 420 mm, the average recharge is 89 mm, and the average specific yield is around 0.03. The data of one water year of 2009 and 2010 has taken for some technical and accuracy reasons.

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