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A field inspector uses a global positioning system receiver to collect data that will be recorded in HYDINFRA. |
The impetus for the development of HYDINFRA (HYDraulic INFRAstructure) came from the district hydraulics engineer’s decision to create a management system for the hydraulic infrastructure on a statewide level. Development of HYDINFRA began in 1996 and was completed a year later. Prior to this, each district either did not collect data for small culverts or had its own way of inventorying and collecting data from paper records to simple databases. Fortunately, there was no catastrophic failure or event that prompted the MnDOT to manage these structures.
HYDINFRA catalogs several types of hydraulic features, as illustrated in Table 1. Although MnDOT does not differentiate culverts from storm drains, there are approximately 50,000 pipes in the inventory. MnDOT estimates that 75 percent of the State-owned pipes have been inventoried. Other than steel and concrete, the inventory has some plastic and corrugated aluminum pipes.
HYDINFRA manages both inventory and inspection data for each hydraulic feature. Examples of inventory and inspection data are shown in Table 2.
HYDINFRA data is used primarily for construction project scoping and to plan maintenance and repairs. Survey crews have used HYDINFRA data to locate culverts for more detailed mapping work. Beginning in 2006, HYDINFRA was used to find features requiring maintenance under the new water quality requirements. Inspection and maintenance activities are logged by date so that the history of problems or repairs is available for each feature.
Field inspectors collect data with global positioning system (GPS) receivers, and the data is then uploaded to an Oracle database. Geographic information tools allow users to query the database for specific information and create maps for use in various projects (see Figure 8). Users can query by condition, need for repair, or need for cleaning.
Hydraulic Feature | Examples |
---|---|
Pipes | Culverts spanning between 12 in. and 10 ft |
Storm Drains | |
Structures | Drop inlets |
Catch basins | |
Manholes | |
Special Structures | Aprons |
Headwalls | |
End treatments | |
Weirs | |
Increasers/reducers | |
Water quality devices | Pond |
Ditch | |
Structural pollution control device | |
Virtual features (added in 2006 to facilitate record keeping for National Pollutant Discharge Elimination System requirements) | Illicit discharge |
Outfalls |
Types of Data | Examples |
---|---|
Inventory | Location |
Type | |
Initial size | |
Shape | |
Material | |
Inspection data | Condition code |
Need for repair | |
Need for cleaning | |
Condition attribute flags | |
Maintenance repairs accomplished and other changes over the life of the hydraulic feature | |
Plan data for proposed features |
Users can access HYDINFRA reports to obtain detailed information about culverts in a specific geographic area. The Pipe Inventory and Inspection Report allows users to specify a highway and the beginning and ending milepost for the area of interest. The report lists information, line by line, about the set of pipes along that stretch of highway (see Figure 9). Data include size, shape, material, and location, plus condition ratings and detailed attribute flags that note problems in the pipes.
Oracle forms allow for data creation, editing, and access. Advanced users complete the Batch Review Form to view newly loaded data (see Figure 10). Forms also interact with the ArcGIS HYDINFRA tools, allowing data to be selected in GIS and viewed in forms and vice versa.
Pipe ID | |||||||
---|---|---|---|---|---|---|---|
588875 | 588876 | 588877 | 588878 | 588879 | 588880 | 588881 | |
MP | 182.79 | 183.82 | 185.05 | 185.58 | 185.83 | 186.07 | 186.96 |
Cond | 2 | 2 | 2 | 4 | 4 | 4 | 2 |
Pipe Shape | Box | Round | Box | Round | Round | Round | Round |
Material | Concrete | Concrete | Concrete | Concrete | Concrete | Concrete | Concrete |
Length | 47.0 ft | 72.0 ft | 57.0 ft | 84.0 ft | 75.0 ft | 66.0 ft | 98.0 ft |
Span x Rise | 72x48 in. | 24x24 in. | 60x60 in. | 24x24 in. | 24x24 in. | 24x24 in. | 30x30 in. |
Cover | 2-6 ft | 2-6 ft | 2-6 ft | 6-10 ft | 6-10 ft | 6-10 ft | 10-20 ft |
Maint. Clean | Y | Y | Y | N | N | N | Y |
Maint. Repair | N | N | N | Y | Y | Y | N |
Repair Under Road | N | N | N | N | N | N | N |
Plugged | N | N | N | Y | Y | Y | N |
Deformed | N | N | N | Y | Y | Y | N |
Standing Water | N | Y | Y | Y | N | N | N |
Infiltration | N | N | N | Y | Y | Y | N |
Silt Present | Y | Y | Y | Y | Y | Y | Y |
Piping | N | N | N | Y | Y | Y | N |
Cracks | N | N | N | Y | Y | N | |
Spalling / Flaking | N | N | N | N | |||
Pitting / Rusting | N | N | N | Y | N | ||
Misalignment | N | N | N | Y | Y | Y | N |
Joints Separation | N | N | N | Y | Y | Y | N |
Holes | N | N | N | Y | Y | Y | N |
Inslope Cavity | N | N | Y | Y | Y | Y | N |
Road Void | N | N | N | N | N | N | N |
Road Stress | N | N | N | N | N | N | |
Erosion | N | N | Y | Y | Y | N | |
Inspection Date | 6/29/2006 | 6/29/2006 | 6/29/2006 | 6/30/2006 | 6/30/2006 | 6/30/2006 | 6/30/2006 |
The cost of replacing large culverts is covered by the statewide general structures budget. There is no dedicated budget for small culverts. The funds are allocated from the general roadway budget to the districts, who then prioritize projects and decide which to undertake.
For local structures, funding comes from the State gas tax, township bridge funds, and bonding. Counties and municipalities set their own budgets, select their own projects, and handle their own designs. On occasion, MnDOT offers assistance with large, complex, or unique structures.
In the absence of any Federal requirements, MnDOT has developed procedures and guidelines for inspection of its massive inventory of culverts and drainage structures. Although the management responsibilities are divided between two units within the Bridge Office that utilize two different management tools, MnDOT has a good handle on its small structure inventory. The use of Pontis is a practical application of an existing software package for CMS purposes. For the smaller structures, HYDINFRA can be used as a model for other States for managing their drainage systems. MnDOT has expressed a willingness to share information on their HYDINFRA with other DOTs. This evolving tool is consistently being enhanced to take advantage of the new developments in computer technology.
MnDOT sees no need for a Federal mandate to inspect culverts, especially since the State has already developed its own procedures. In fact, MnDOT maintains that a Federal mandate could be a burden to local governments. This view is consistent with the position already adopted in 2005 by the AASHTO Subcommittee on Bridges and Structures.
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Shyan-Yung Pan
Office of Asset Management
202-366-1567
E-mail Shyan-Yung
Wade Casey
Office of Asset Management
202-366-4606
E-mail Wade