Legend

« m Soil and vegitation samplesites - Wetland Boundary and transect

- Plant Association

FIGURE 5.12 Example: wetland delineation.

Public Works Management Information System

Public works facilities—water mains, sanitary sewer lines, storm drains, and street improvements—provide the infrastructure essential for urban life. The efficient management of public works requires detailed knowledge about the configuration, condition, and performance of each of the various systems of public works serving the urban area. Such knowledge requires not only the collection of data about the system to be managed, but also the conversion of that data through analyses into pertinent information, and then, by the exercise of professional judgment, into intelligence on the basis of which sound management decisions can be made.

Historically, data about public works were kept on paper records, such as file index cards, construction plans, as-built construction records, special-purpose maps and plats, and written reports. Sometimes, the data resided only in the living memory of staff. The records were often duplicative, poorly maintained, difficult and time-consuming to access and use, and not well coordinated between different functional areas such as tax assessment, planning, and engineering. When meticulously kept and well indexed, such manual systems have worked tolerably well, particularly in smaller communities. As the size and complexity of a community increases, however, the use of manually kept records becomes increasingly difficult and unsatisfactory. The means now exist for the modernization of these records and, therefore, of their conversion into an efficient and effective computer-based public works management information system. The existence of such systems greatly facilitates the conduct of environmental engineering studies and assessments, as well as the preparation of facility system plans.

Two developments make such computer-based public works management information systems possible: the development of powerful, yet relatively low-cost and user-friendly, microcomputer systems; and the development of high-quality, automated base maps. Together, these two developments provide the basis for the creation of parcel-based, automated, land information systems, and in turn, automated public works management information systems. The control survey and mapping system described herein provide a sound foundation for the creation of these land information and public works management information systems.

Figure 5.13 illustrates use of the control survey and mapping system in the development of a public works management information system for a sanitary sewerage system. The addition of sanitary sewerage facilities to an automated base map is valuable in and of itself. Such addition permits sewerage system maps to be readily produced at various scales for analytical and display purposes. If a common control survey and mapping system is used, the sewerage system mapping can be readily correlated with other public and private utility system maps. Importantly, service areas can be delineated for analytical and design purposes, and these service areas can be correlated with real property boundary maps. The sanitary sewerage facilities should be delineated on a base map consisting of a combination of selected features drawn from the available

FIGURE 5.13 Portion of a public works information system base map with sanitary sewerage system overlay.

topographic and cadastral maps to provide the necessary foundational element for the facility mapping. The topographic map provides information on building locations and pavement lines; the cadastral map on property boundary and street rights-of-way lines. Since the two maps are constructed on a common projection—the State Plane Coordinate System—the existing sewerage system can be readily inventoried by field surveys using global positioning system techniques for both horizontal and vertical positioning determination. New facilities can then be readily added through the preparation of proper as-built records tied to the State Plane Coordinate System and common vertical datum. Spatial location identification numbers are provided for manholes, and attendant data on manhole rim and sewer invert elevations, and on segment sizes, lengths, and grades added together with service area delineations.

Although the accurate mapping of the facilities is valuable in and of itself, the creation of a public works management information system requires the systematic development of a set of facility attribute data that can be linked by computer to the geographic location data provided by the automated base map. The attribute data files provide information on the structural type, condition, and performance of the facilities concerned. Creation of the attribute data file for each facility system should be accomplished in accordance with detailed memoranda that clearly specify the form and content of the computerized attribute data file. Attribute data for the sanitary sewerage system should be structured to facilitate efficient planning, design, construction, operation, and maintenance of the system. The scope and conduct of the data file should be structured in close cooperation with the director of public works, the city engineer, and system operating and maintenance personnel. A typical list of attribute data is provided in the following.

Sanitary Sewerage System Attribute Data

I. General

A. System name

B. System number

C. Primary contact

II. Gravity flow sanitary sewers—data by segment between manholes

A. Identification number

B. Date of construction

C. Material

D. Pipe size in inches

E. Pipe length in feet

F. Grade in feet per foot

G. Manholes

1. Type

2. Cover

3. Location—State Plane Coordinates, NAD-27

4. Rim elevation in feet, NGVD-29

5. Invert elevations in feet, NGVD-29

H. Capacity flowing full in cubic feet per second

I. Flow in cubic feet per second

1. Average daily

2. Instantaneous peak

J. Surcharge elevation in feet, NGVD-29 K. Overflow

1. Gravity flow a. Size in inches b. Length in feet c. Location in State Plane Coordinates, NAD-27

d. Invert elevation in feet, NGVD-29

e. Materials of construction f. Capacity in cubic feet per second g. Frequency h. Duration i. Rate in gallons per day j. Receiving watercourse

2. Pumped a. Type b. Location in State Plan Coordinates, NAD-27

c. Rated capacity d. Idling capacity e. Frequency f. Duration g. Receiving watercourse L. Condition

M. Service connections

1. Identification number

2. Date installed

3. Location in cumulative feet from downstream manhole

4. Lateral size in inches

5. Material

6. Service street address N. Service area in acres

O. Construction plans P. Construction as-built drawings Q. Plan proposals R. Instrumentation 1. Flow meter a. Manufacturer b. Model and serial number c. Date installed d. Calibration e. Supervisory control and data acquisition system f. identification link to historical database g. Correction factors

2. Flume a. Manufacturer b. Model and serial number c. Date installed d. Calibration

3. High-level/surcharge monitor a. Manufacturer b. Model and serial number c. Date installed d. Calibration e. Supervisory control and data acquisition system f. identification link to historical database S. Pumping and lift stations data by station

1. Identification number

2. Date of construction

3. Location in State Plane Coordinates, NAD-27

4. Floor elevation, NGVD-29

5. Type

6. Capacity a. Pump

(1) Manufacturer

(2) Model and serial number

(3) Date installed

(5) Capacity at operating head in cubic feet per second

(a) Manufacturer

(b) Model and serial number

(c) Date installed

(d) Starter type

(e) Horsepower

(f) Voltage b. Wet well storage-gallons c. Power d. Auxiliary

(1) Generator

(a) Manufacturer

(b) Model and serial number

(c) Horsepower (2) Engine

(a) Manufacturer

(b) Model and serial number

(c) Horsepower

(e) Cooling T. Influent pipes

1. Sizes in inches

2. Invert elevations in feet, NGVD-29

3. Capacities flowing full in cubic feet per second U. Effluent force main

1. Size in inches

2. Length in feet

3. Receiving facility

4. Materials of construction

5. Capacity in cubic feet per second V. Emergency bypass

1. Outfall a. Location—State Plane Coordinates, NAD-27

b. Size in inches c. Length in feet d. Invert elevation in feet, NGVD-29

e. Materials of construction f. Capacity in cubic feet per second g. Receiving watercourse

2. Bypassing a. Frequency b. Duration c. Rate in gallons per day W. Construction plans

X. Construction as-build drawings Y. Service area

1. Size in acres

2. Resident population

3. Commercial area in acres

4. Industrial area in acres

Z. Plan proposals AA. Instrumentation and controls

1. Controller a. Manufacturer b. Model and serial number c. Date installed d. Date serviced by e. As-built drawings

2. Instrumentation a. Manufacturer/model and serial number b. Date installed c. Date calibrated d. Date last serviced III. Treatment plant: data by plant

A. Plant identification number

B. Type of plant

C. Date of construction by major treatment units

D. Site, location—State Plane Coordinates, NAD-27—of site boundary, site area, in acres

E. Hydraulic capacity by major treatment units

F. Hydraulic loading by major treatment units

G. Biological capacity by major treatment units

H. Biological loading by major treatment units I. Plant capacity in population equivalent

J. Plant loading in population equivalent K. Permit effluent quality L. Operating effluent quality

1. Dry weather flows

2. Wet weather flows M. Outfall

1. Size in inches

2. Length in feet

3. Invert elevation in feet, NGVD-29

4. Materials of construction

5. Capacity in cubic feet per second

6. Receiving watercourse N. Bypassing

1. Frequency

2. Duration

3. Rate in gallons per day O. Construction plans P. Construction as-built drawing

Q. Replacement cost by major treatment unit and total service area

1. Size in square miles

2. Resident population R. Plan proposals

Similar tables listing attribute data for public water supply, stormwater management and street systems can be developed to provide a comprehensive public works management information system. The existence of the resulting public works management information system can greatly facilitate the conduct of environmental planning and engineering studies and assessments; the assessment of the condition and performance of existing systems; the existence of environmental problems relating to the existing systems; and the preparation of system, preliminary engineering, and construction plans.

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