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Appendix K

Groundwater Overdraft Reduction Measures

I. GENERAL The proposed Gateway lies within Root Creek District (District). The District has entered into an agreement with the Madera District, Chowchilla Water District and the Friant Water Users Authority that requires the District to reduce the groundwater overdraft within the District. The groundwater overdraft in the District has been estimated to be 3,400 acre-feet per year in a report entitled the Hydrogeological Investigation of Southern Madera County by Ken Schmidt & Associates in 2001.

It is important to note that the proposed Gateway Village comprises only 2,062 acres of the approximately 9,000-acre Root Creek Water District.

II. GROUNDWATER OVERDRAFT REDUCTION MEASURES

In order to address the requirement of eliminating the groundwater overdraft within the entire District, the following programs will be implemented.

1. Change in Overdraft from Development of Property

The annual demand for the proposed Gateway Village is estimated to be 6,374 acre-feet. This estimate includes demand for parks that may ultimately be met by the reuse of treated wastewater. This is marginally less than the estimated existing demand of 6,450 acre-feet for within the boundary of the proposed project. Ken Schmidt & Associates (2001) estimated the average annual demand based upon the original Gateway Village project boundary and the existing, predominantly agricultural uses, but this estimate included approximately 350 acres of land south of Avenue 10. Assuming a demand of 3.0 acre-feet per acre for the 350 acres, the estimated existing annual demand within the current project boundary is 6,450 acre-feet.

2. In-Lieu Program

Construction of a pipeline from the Madera Irrigation District’s Lateral 6.2 will allow for delivery of to agricultural within the Root Creek Water District. These lands have historically used only groundwater. As identified in Appendix D, this program will provide an average annual surface

i:\clients\castle & cooke - 1434\14340302-imp\ master plan\current 0906\0906 draft\clean\k - groundwater impact.doc 1 of approximately 2,302 acre-feet, thereby reducing groundwater extraction by that amount.

3. Reclamation of Treated Wastewater

Treated wastewater will be delivered agricultural land areas within the Root Creek Water District that are outside of the proposed Gateway Village. These lands are designated in Figure 2 of the IMP Executive Summary as the Effluent Disposal Area. Currently planted in citrus, these orchards currently rely solely on groundwater to meet the agricultural water demand. As shown in Appendix H, an estimated average of 1,767 acre-feet will be available for reclamation. The amount delivered relates directly to the reduction of groundwater pumping by this program.

As described in Appendix F, treated wastewater may be delivered to large irrigation areas within Gateway Village. The amount of treated wastewater delivered for this purpose would reduce the amount of potable water needed for project irrigation by that same amount.

Wherever is applied, the overall groundwater balance would be the same, since any effluent not used for project irrigation would be used for irrigation of agricultural crops within Root Creek Water District which would otherwise require irrigation by pumping groundwater.

4. Recharge by Conjunctive Use of Facilities

Storm water facilities will be used for intentional during months when these facilities are not needed for stormwater control. The structures in Root Creek that are identified in Appendices C and I will be utilized. An estimated 990 acre-feet per year can be recharged, assuming an infiltration rate of 0.15 feet per day, a wetted area of 55 acres, and that water is available for 120 days. These assumptions were based on information presented in Appendix C.

5. Groundwater Recharge Basin

A groundwater recharge facility will be constructed as identified in Appendix C, near 35. It is estimated that the proposed basin will recharge 960 acre-feet of water per year. Approximately 1,000 acre-feet per year can be recharged, assuming an infiltration rate of 0.3 feet per day, a wetted area of 28 acres, and that water is available for 120 days. These assumptions were based on information presented in Appendix C.

i:\clients\castle & cooke - 1434\14340302-imp\infrastructure master plan\current 0906\0906 draft\clean\k - groundwater impact.doc 2 Table 1 shows the total potential groundwater impacts based on the capabilities of the proposed measures, but is not intended to be an operational commitment on the part of the project proponent.

Operationally, some programs will run in some years but not in others, and RCWD will choose how to meet the 3,400 acre-foot per year annual recharge commitment in the most effective and economical way available.

Table 1 - Groundwater Recharge Potential of Facilities Impact of Gateway Village at Full Build-Out

Overdraft Change Cumulative Overdraft Description (AF/yr) with Changes (AF/yr) Total Estimated Current Overdraft in RCWD (from Hydrogeological Investigation of Southern Madera County, Schmidt, 2001) -3,400

Groundwater Overdraft Reduction Programs Change in Overdraft from Development of Property [Difference between Total Project Water Demand (6,374AF/yr at 1 buildout) and Current Use from Schmidt 2001 (6,450AF/yr)] 76 -3,324 In-lieu Program 2 (Reduced by Developed Acreage, from In-Lieu Update 7/2006) 2,302 -1,022 Reclamation of Treated Wastewater 3 (Estimate from Infrastructure Masterplan) 1,767 745 Recharge by Conjunctive Use of Stormwater Facilities 4 (Structures along Root Creek) 990 1,735 Recharge at Dedicated Recharge Basin 5 (Root Creek Basin at Road 35) 1,000 2,735

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