CO2500082 - Laserfiche WebLink

Home Browse Search

Below is the evaluation summary for the 2368 W.Woodward Irrigation Well (APN 24126040)-well permit application. The evaluation,with assumptions as noted, indicates that the proposed Irrigation well is located in an area of low domestic/residential well density(1 well per section), but is not likely to interfere significantly with existing off-site wells,create unreasonable groundwater level declines/reductions in aquifer storage or to create issues with infrastructure due to subsidence and it can be approved pending any other issues that you might have with the application. Summary: - Extraction rate—440 GPM with anticipated pumping schedule 84,600 BGal/day or 58.75 GPM - Proposed new well is in an area of low domestic/residential well density (2 well per section). A possible domestic well is located approximately 1200 feet South of the proposed Ag well - Online databases do not specify any irrigation wells located within 2,000 feet of the proposed well location. Review of aerial imagery indicates an irrigation well is present approximately 2200 feet West. - This well is proposed to irrigate the park (4.93 acres) for the proposed Trails of Manteca subdivision within the City of Manteca where public water and sewer will be provided for the subdivision. - The applicant proposes:well depth of 200 feet, a well grout seal of 50 feet, and a maximum pumping rate of 440 GPM. - Groundwater levels estimated by DWR well data (Station 377742N1212713W001) range between 8 to 22 feet below ground surface over the past fifty years.Water levels fluctuate approximately 3 to 11 feet between seasonal high and low levels. - The permit application proposes a minimum well casing/grout seal of 50 feet and appears to target the Modesto/Laguna aquifer with water-bearing zones anticipated to be under unconfined to locally confined conditions. - The annual total extracted volume is estimated to be approximately 195 million gallons,a peak pumping rate of 440 (Q4)GPM,and an annualized/seasonal pumping rate of approximately 646 (R2)GPM. - The aquifer volume below the 199.97-acre parcel contains an estimated 9,599 acre-feet of water storage.The proposed extraction volume of 14.79 acre-feet per year is approximately 0.2%(X2)of the estimated aquifer storage beneath the parcel without regard to recharge each season and is considered sustainable. - The proposed well is located within the extents of the Corcoran Clay, approximately 200 foot below ground surface.The subsurface water-bearing sediments are semi-consolidated to consolidated,and the proposed well is 200 deep,which is not located in an area where subsidence is currently indicated,therefore subsidence is unlikely to be of significance or to create issues. Aquifer Model results: - The Maximum drawdown at the proposed Ag pumping well is estimated to be less than four foot at peak pumping rates of 440 GPM with a radius of influence of 1200' - The maximum predicted drawdown 1,200 feet from the proposed AG well approximately less than four feet during sustained seasonal peak pumping rates.The conservative case(confined aquifer model) predicts less than four foot of drawdown at a distance of 1200 feet as a result of long-term,sustained pumping at the maximum pumping rate of 440 GPM.