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\~t -,'>-l . OOOOG(} South Platte Water Rights Management System Spatial Data Types Linear Data The map features used by the SPWRMS application are of two types -linear and point. The layers which contain linear features, such as aqueducts, ditches, reservoirs, and streams, were distilled from files purchased from the Earth Science Infonnation Center (ESIC), a branch of the U.S. Geologic Survey (USGS) which handles digital cartographic data. Layers containing point data, such as diversion structures and stream gauges, were compiled by CADSWES personnel and digitized from various paper map sources. Most of the data which make up the map layers were purchased from the ESIC. These data were in the fonn of digital line graphs (DLGs) from the USGS 1: l00.ooo-scale topo- graphic map series. DLGs consist of linear features which have many associated attributes in a coded. numerical fonnat. Each quadrangle has four DLG layers of coded line infor- mation. Only the hydrography layer, which contains all natural and human-made water features, was used to develop data for SPWRMS database. The South Platte River basin falls on portions of fifteen maps from the USGS 1: l00,ooo-scale topographic map series. Hydrography data were taken from the following USGS quadrangles: Bailey. Castle Rock, Denver East, Denver West, Eaton, Estes Park, Fott Collins, Fort Morgan. Greeley, Gunnison. Julesburg, Leadville. Pike's Peak. Sterling. and Wray. The DLG files obtained from ESIC were converted to Arc/Info layers using import utili- ties. These layers were then mosaic-ed to produce one large coverage containing the whole basin project area. Coded line attributes were preserved during the conversion from DLG to Arc/Info format and used to separate the mosaic map into the six layers used by the SPWRMS application. Specific data development considerations for each of these six layers are mentioned in the following sections. . Point Data Point data for SPWRMS database, such as locations and names of stream gauges and diversion structures, were obtained primarily through personal contact with Division 1 water officials. These data were entered into the spatial database by hand digitizing the locations from paper 1 :24,000-scale topographic maps. Streams Layer The streams linear layer contains all rivers and tributaries in the project area which contain diversion structures and/or stream gauges referenced by SPWRMS. This layer forms the skeleton of the in-memory data structure (the network tree) used for modelling basin dynamics. . Development The spatial data of the streams layer required extensive manual editing to be developed into a usable fonnat. The topology of this layer must be defined such that it can be used to generate a directed graph connecting all stream gauges and diversion structures. There- fore, aHline segments must be connected, have consistent direction and not be continuous through a point where a gauge or structure is located. Problems with the raw data that interfered with this topology were mismatched line segments where edge matching had been performed between quadrangles, inconsistent line directions relative to flow direc- tion, and line segments that did not break at the site of structures and stream gauges. Arc/Info macros were developed by CADSWES for processing the stream network to ensure that connectedness and directedness requirements were satisfied (hand editing was performed where necessary). Where streams passed through a reservoir, one of the reser- Database Manual 15