Laserfiche WebLink
6. Historic Water Source Assignment <br />A stepwise approach was used to assign a water source to the historic irrigated parcels. The 2001 <br />irrigation service areas described in SPDSS Technical Memorandum 91 were used as a starting point. <br />Historic diversion records were used to gain more information on when diversions were current. <br />Irrigation wells were then assigned to the irrigated parcels to supply a groundwater source. Well <br />assignments from 2001 were translated to the historic parcels. Parcels not mapped in 2001 were matched <br />to wells using the State DGI well-o-parcel matching program. Figure 11 shows a flow chart of the well <br />assignment process. <br />Identify historic diversion structures. Create <br />list of diversions for each historic period <br />Create Historic Ditch Service Areas for each <br />historic period <br />py service area from subseq~ <br />to use as starting point <br />Create service areas for historic diversions <br />that have not yet been mapped <br />Identify Parcels Not in a Service Area <br />Locate parcels not in a service area. Edit <br />service areas or re-evaluate irrigated status. <br />Check Irrigated Acreage With Diversion <br />Records <br />Compare GIS acreage with historic diversion <br />n Diversion IDs to Historic Parcels <br />WDID from diversion and service area <br />Historic Parcel to Well Assignment <br />Assign irrigation wells to irrigated parcels <br />Assign Wells to Parcels Based on 2001 Well <br />Assignments <br />Translate well assignments from 2001 parcels to <br />historic parcels using centroid approach <br />Parcels not mapped in 2001 and each subsequent historic <br />Figure 11. Overview of SPDSS irrigated parcel historic water source assignment. <br />Page 19 of 59 ~Rrvers~dk+ 9ecbnoingyl,. ~rlco <br />r ~-~a.,. - „~,. <br />