Ditch Record Modernization Status
The Ditch Records Modernization (DRM) project for the Bois de Sioux Watershed District was meant to be a starting block for the 60 ditch systems under our jurisdiction. We acknowledge that DRM has two different approaches as to its meaning; one, being the duplication of hardcopy records to a more distributable and back-up friendly form of digital media; the other, to utilize modern technology to better access and interact with the original records/designs/data in conjunction with modern records/surveys/data of a given ditch system. Our hope was to take a sample size of 10 ditch systems to copy current records to a digital format, as well as design a GIS template on the JD 11 system that can be replicated for the remaining ditch systems throughout the district.
JD 11 Background
The JD 11 system is located in western Minnesota in the Bois de Sioux Watershed; specifically in northern Traverse County and southern Wilkin County. Its 30.1 miles of open ditch consists of an east-west oriented main (6.6 miles), a north-south oriented main (5.8 miles), and 10 individual laterals (17.7 miles). The system outlets into the Bois de Sioux River, roughly 14 miles upstream of Breckenridge, MN.
Hardcopy to Digital Processing
Most of the current ditch records are located at the district office in Wheaton, MN, or at the engineering consultant's office in Alexandria, MN. This alone is a great reason to create digital media so multiple sources of key users can view the data with ease. The other reason is for preservation. With any number of catastrophes that can befall on records kept in any location…the ability to have digital copies that are replicated and located in different sites can preserve the records. As part of the project, the district purchased a legal sized flatbed scanner and scanned all records up to legal size using the jpg format at 300 dpi. For large format scanning of plan sets, maps, etc, we utilized Mathison's document scanning services in Fargo, ND. The tiff format at a resolution 400 dpi was used. The file naming convention is based on the recommendations made in the Board of Soil and Water Resources Drainage Records Modernization Guidelines, September 2008, Section 9.2.3. http://www.bwsr.state.mn.us/drainage/records_guidelines.pdf The district purchased external HDD's to store this data. The HDD's will be stored at separate buildings to help buffer natural disasters (such as flooding or fire). A laptop computer was purchased for Assembling the data, mobile use to access ditch records in the field, at board meetings, public meetings and display for public questions re: a ditch system.
JD11 Modernization via GIS
For the DRM portion in which we better utilize current computer technologies to access and use both old and new ditch records simultaneously, we used a Geographic Information System (GIS). This enabled us to:
- Easily access the scanned documents as attachments to geographic features (ditch lines).
- Gives us a user friendly environment of an on-screen map for location and presentation.
- Through the use of Linear Referencing, we can dynamically add spreadsheet derived records and inventories to the ditch system (both spot and linear data based on design stationing).
- Take existing data sets (ie. culvert inventory, streamgages, etc), and attach stationing information to them.
- Generate ditch specific datasets that are based on the ditch stationing.
- Run spatial analysis of common datasets (soils, LU, NWI, etc) based on length and width characteristics.
- Inspect ditches with on-screen GPS location shown in regards to ditch position. Making the recording and distribution of inspection results easy and archivable.
- Accurately enhance LiDAR elevation models that have poor accuracies in the ditch itself due to biotic growth or standing water.
The geographic features (ditch lines) were generated by creating a best fit horizontal line in AutoCAD from surveyed measurements of the ditch centerline. This horizontal line was broken into segments at each change in the ditch characteristic (i.e. bottom width, side slope, gradient or horizontal alignment change) with the legal constructed grade and station at each node. The segments have a corresponding row in the Linear Referenced spread sheet. The digital output from an AutoCAD drawing to an ESRI shapefile (polylineZ) maintained its 3D attributes and all segments were joined to a single line based on the ditch name (ie JD 11 Lat 3). This was then brought into ArcINFO 10.0 and transformed into a routed Geodatabase feature (polylineZM). This routed line is now able to utilize any Linear Referencing commands in any ESRI ArcGIS software package.
New with ArcGIS 10.0 is the ability to attach multiple files (tif, jpg, pdf, doc, etc.) to any given feature utilizing ESRI's Attachment feature. This enables us to link numerous ditch specific files that were scanned for the ditch system to any or all of the line segments allowing the user to access scanned ditch records immediately.