UNITED STATES DEPARTMENT OF COMMERCE October 13, 1981 OA/W22
TO: All Holders of Operations Manual
SUBJECT: Transmittal Memorandum for Operations Manual Issuance 81-16
1. Material Transmitted:
WSOM Chapter E-20, Hydrologic Reporting Networks (26 pages).
2. Summary:
This chapter has been rewritten and retitled with instructions expanded to meet current operating conditions.
a. The Hydrologic Reporting Station Network Improvement data set is described (2).b. River Station Description and History has been added (4).
c. Instructions requesting the U.S. Geological Survey to continue river gaging stations are outlined (5).
d. Documentation of Flash Flood Alarm Systems is included in this chapter (6).
e. Exhibits have been added.
3. Effect on Other Instructions:
This chapter supersedes the following:
a. WSOM Chapter E-20, Management of Networks, Issuance 70-18, dated May 27, 1970.b. OML 20-74, dated June 19, 1974, filed with E-20.
c. OML 23-75, dated November 12, 1975, filed with E-20.
d. OML 9-80, dated June 10, 1980, filed with E-20.
Elbert W. Friday, Jr
Director, National Weather Service
Issue Date Org. Code NATIONAL WEATHER SERVICE Part Chap.
10-13-81 W22 Operations Manual E 20
HYDROLOGIC REPORTING NETWORKS
Table of Contents:
1. Purpose*2. Establishment of Substations
2.1 Requests by Weather Service Forecast Office/Weather Service Office (WSFO/WSO) Hydrologic Service Areas (HSA's)
2.1.1 Statement of Requirements
2.1.2 Flash Flood Networks
2.1.3 Hourly Precipitation Network
2.1.4 Evaporation Network
2.2 Requests by Other Government Agencies
2.3 Designation of Hydrologic Substations3.1 Observers
3.2 Substation Instruction
3.3 Supplies
3.4 Inspection*4. River Station Description and History
4.1 Report on River Gage Station, WS Form E-19
4.2 Abridged Report on River Gage Station, WS Form E-19a*5. Request for Continued Operation of a U.S. Geological Survey (USGS) River Gaging Station
Exhibits:
E-20-1 WS Form E-19 Report on River - Gage Station
E-20-2 WS Form E-19a Report on River - Gage Station
E-20-3 Draft Letter to USGS
E-20-4 WS Form B-44A Report on Substation (Flash Flood Alarm System)
1. Purpose. The chapter describes the procedures for establishment, modification, and administration of the National Hydrologic Reporting Networks and the National FC-1 Hydroclimatic Network. Detailed information on substation management and a description of terms and forms is contained in WSOM Chapter B-17.
* 2. Establishment of Substations. The Regional Director is the approving authority within available resources. The regional hydrologist establishes requirements, provides the technical supervision, interregional liaison, and interagency coordination of requests for the establishment of substations in the "b" and "ab" networks. The intraregional administrational supervision for the establishment and maintenance of all substation program and direction of substation network specialists (SNS's) is provided by the regional Data Acquisition Division primarily through the Regional Substation Management Branch/Staff (RSMB/S) (see WSOM Chapter B-17).
2.1 Requests by Weather Service Forecast Office/Weather Service Office (WSFO/WSO) Hydrologic Service Areas (HSA's). Regional headquarters is the approving authority for the establishment of and implemented changes in "b" (hydrologic) and "ab" (hydroclimatic) substations within resources available to the regions. (These networks are defined in WSOM Chapter B-17 and other directives.) Resources include costs of station equipment, maintenance, observer fees, communications, etc. When the need for the establishment or modification of a substation or a number of substations in the reporting network in a WSFO/WSO Hydrologic Service Area (HSA) becomes evident, the meteorologist in charge (MIC) responsible for the hydrologic network for that designated WSFO/WSO HSA will submit WS Form B-43 to the regional headquarters (RSMB/S). This form is required for each proposed change in substation location or fees of established substation observers, as well as for a proposed new substation.
The contents are analyzed by the regional hydrologist and RSMB/S for agreement with stated requirements (see following paragraph), approval, and implementing action. WS Forms B-44, B-23, B-30, and E-19, which are discussed in WSOM Chapter B-17, should be prepared or the data for their preparation should be obtained at the time of the establishment of substations.
2.1.1 Statement of Requirements. Before a new hydrologic reporting substation is authorized, the proposed location should be compared by the regional hydrologist and River Forecast Center (RFC) with the planned network given in the Hydrologic Reporting Station Network Improvement (HRSNT) data set. This is a file of current reporting stations or locations requiring additional reporting or locations proposed for improvements. The file constitutes the statement of requirements for the hydrologic reporting station network for hydrologic services. Criteria for the network density of hydrologic reporting stations were based on the research of Kohler (Casebook on Hydrologic Network Design Practice, WMO - No. 324, 1972). The file is maintained by the Office of Hydrology, to reflect an up-to-date status of the basic hydrologic reporting station network with the assistance of the field. Responsibilities for its maintenance are as follows.
a. Office of Hydrology (O/H) will:
(1) Review regional headquarters' requests for changes to the HRSNI data set. O/H will enter changes into the data set as soon as possible.(2) Prepare listings from the HRSNI data set. Lists will be made available to the regional headquarters, RFC's, and other users.
(3) Prepare maps of station locations from the data set.
(4) Coordinate station automation requirements with the Office of Meteorology and Oceanography.
(5) Designate locations from the HRSNI data set at which equipment purchased by the Office of Technical Services (OTS) for improving the hydrologic reporting station network should be programmed for installation. These designations will be coordinated with the regional headquarters and other agencies.
(6) Transmit stated requirements to OTS for equipment planning.
b. Regional Headquarters will:(1) Ensure that locations exchanged for others listed in the HRSNI and mass [O/H a.(3)] will be entered onto these documents.(2) Exchange a precipitation reporting location in the HRSNI data set for each substitute precipitation reporting location that is added to the plan. River reporting location may be added to the plan if they are forecast points. A precipitation station may be added to the plan for each additional river reporting location.
(3) Notify the O/H about changes to the HRSNI data set. This action may be made necessary by: site surveys, field installations, adding reporting locations, or correcting data in the file. RFC's should summarize all changes to their river station file for the previous 12 months from September. This information should be attached to the Activities Report each September.
The Pacific Region, Puerto Rico, and the Virgin Islands are not included in this activity because criteria for the hydrologic data requirements in those areas differ from those for other regions. Requirements for these areas will be handled on a separate basis.
2.1.2 Flash Flood Networks. Flash flood warning networks are established in headwater areas subject to flash flood where the time interval between the rain and flood is too short to allow flood forecasts to be issued from a centralized forecast point. In such situations, consideration should be given to developing one network that will serve as a severe local storm reporting network as well as a flash flood warning network. These stations should be documented at the WSFO/WSO/RFC's to ensure their use during emergencies by Weather Service personnel.
On occasion, an observer will be paid by the National Weather Service (NWS) to collect and telephone special reports from the reporting network to a specific WSFO/WSO/RFC. This type of station has to be established in the "b" network following guidelines in WSOM Chapter B17.
2.1.3 Hourly Precipitation Network. The NWS operates about 3100 recording-type rain gages owned both by the NWS and other Federal and local agencies. Regional headquarters approve changes to the recording rain gage network in accordance with WSOM Chapter B-17. The objective is to have all data published by Environmental Data and Information Service (EDIS) in the appropriate state Hourly Precipitation Data (HPD) series. Several hundred additional rain gages located at stations in the substation program could produce hourly data for publication, but their records are not presently published by EDIS.
2.1.4 Evaporation Network. The NWS operates about 440 evaporation stations. Most of the daily observations are published by EDIS in the state Climatological Data (CD) series. Those stations operated for hydrology are in the "b" and "ab" networks (see Chapter B-17). The regional hydrologists manage the location of these stations while the RSMB/S's manage the maintenance and quality control of these stations.
2.2 Requests by Other Government Agencies. Requests received by field offices for the establishment or modification of a reporting network or other cooperative reimbursable projects for hydrologic purpose must be referred to the appropriate regional headquarters. The establishment of substation services in a cooperative project to be operated on a reimbursable basis must be authorized by the NWS Headquarters (WSH) (see WSOM Chapter B-17). Minor changes in existing cooperative projects do not require coordination except for funding transfers from the requesting agency.
Inauguration of the service will be made by the regional Data Acquisition Division. A project should not be started, however, until all arrangements are completed with a cooperating agency and authorization received from WSH.
The (FC-1) network is essentially a nationwide network of precipitation gages to obtain data for planning purposes especially for the Corps of Engineers (CoE) (see WSOM Chapter B-17). Changes in this network are principally station relocations (gage transferred to a compatible site) and station moves (gage transferred to non-compatible site). The latter will require coordination with the appropriate district office of the CoE by the regional hydrologist.
Cost accounting at the field level for reimbursable project is accomplished by indicating on all vouchers the appropriate funding code number assigned to the project. Offices responsible for allocating costs on communications vouchers must know which messages are charged to specific projects.
2.3 Designation of Hydrologic Substations. The terms used for service designation should be Precipitation, Recording, Rainfall (river), etc. followed by project fund designation. (For example, "Recording - FC-1," "River S&E (Hydro)," "Rainfall IRPN-2," "Precipitation S&E," etc. Check WSOM Chapter B-17 for definition of these terms.)
3. Administration. Substation activities pertaining to real-time river and rainfall reports are supervised by the WSFO/WSO with assigned HSA responsibility. Some Weather Service offices may be.referred to as collection centers to collect and transmit data to RFC's. (Regions will issue an ROML to explain variances to the description in this chapter.) At multipurpose substations, any action with respect to these two services will be coordinated with or through the regional headquarters. Details of coordination (not to be confused with supervision) will include the following: observer appointment, issuance of supplies, certification of quarterly substation payroll, and substation inspection, or other documentation and services. In any event, the regions determine the individual who carries out these details to completion.
3.1 Observers. While in most cases river and rainfall observers are paid for their services, the remuneration is very modest and does not entirely take them out of the category of cooperative observers. The approach, therefore, to the individuals who are prospective appointees and subsequent relations with them after they are appointed do not differ much from the way of dealing with cooperative unpaid substation observers in any service of the Weather Service. The appointment of an observer requires the preparation forms as noted in WSOM Chapter B-17.
3.2 Substation Instruction. The SNS and WSFO Service Hydrologist issue instructions to observers for making observations and transmitting the data. However, the observer contact is the SNS who should instruct observers to prevent conflicting instructions and to ensure proper documentation. Standard instructions for river and rainfall, river, and rainfall (river) substations are printed on WS Forms E-11, E-11a, E-12, E-12a, and E-13, respectively. These instructions may be modified according to the criteria of reporting and methods of the transmission of data as the needs of individual supervising may require. An effort should be made to adhere to the instructions given in those Weather Service forms so all WSFO's/WSO's with an assigned HSA issue guidelines that are uniform. The abridged Weather Service form should be made available to the observer for posting near his telephone.
3.3 Supplies. WSFO/WSO's with an assigned HSA are responsible for keeping substations under their supervision supplied with the necessary forms, franked envelopes, carbon paper, pencils, and other materials needed for recording and transmitting data. Each region may amend this procedure by ROML, but it is suggested that an annual review of stations be made so new personnel at WSFO/WSO will know what actions to take.
3.4 Inspection. Substations with reporting network duties should be inspected at least once each year by the SNS or WSFO/WSO official within whose area of assignment the HSA substations are located. An annual visit by either the WSFO/WSO official or the WSFO service hydrologist is desirable since these personal contacts with substation observers materially aid the effectiveness of the substation program. All NWS personnel involved in the service programs should participate to some degree.in these station visitations. Arrangements for use of the services of the SNS are made by contacting the RSMB/S. Travel should be planned in advance so that the needs of all services can be coordinated and, if the SNS is involved, so that the work can be fitted into the schedule of routine travel plans. Details of the work to be performed during inspections of substations and other pertinent information are contained in the National Weather Service Substation Inspection Guide in WSOM Chapter B-73, Station Visitation Procedures - Substations. If instrumental trouble develops or a change of observers is necessary between the annual inspections, special trips either by WSFO personnel or the SNS should be arranged in the same manner as the regular trips. In case of shortage in personnel or for other reasons, arrangements may be made for maintenance or leveling work at the river gaging substations with the district office of the USGS or the CoE. Occasionally such arrangements may involve interdepartmental transfer of funds; they should be made only when absolutely necessary and with prior approval of the regional headquarters. When the WSFO/WSO official visits the substation(s) in place of the SNS, arrangements should be made to complete forms needed by the SNS and RSMB/S.
*4. River Station Description and History.
4.1 Report on River Gage Station WS Form E-19. Exhibit E-20-1 illustrates how WS Form E-19 provides a complete history of the station and all gages that have been used for public forecasts since establishment of the station. It is a vital tool for operational reference and a quick review of the public service needs within a particular river reach at the onset of and during a flood, especially the River Stage Data sheet (WS E-19, page 9). Officials who need to know the effect of the river forecast or the prevailing stage should have a copy of this chart.
Beyond this important function, there are other immediate and continuing values. The drawing together of all necessary reference material, the study of this material and its organization in response to instructions within the form, the field visitation to the gaging station and the river reach served by it, all help provide an intimate knowledge of a particular area and an appreciation of the vital importance of the river and flood forecasting service in saving life and property. An equally important and longer term value is the self-training function for the individual(s) involved in the preparation of the report as well as the use of the report itself as a reference document in the continuing education of all staff members in the station's hydrologic service program.
The E-19 should be updated and rewritten every 10 years for each river station.
4.2 Abridged Report on River Gage Station WS Form E-19a. Exhibit E-20-2 is a one-page summary illustrating how WS Form E-19 updates and confirms the basic station information. Preparation of this form is the responsibility of the WSFO/WSO with assigned HSA. Following is a summary of requirements for the initial rendition and future revisions.
a. WS Form E-19a should be on file for all river gaging stations used by the NWS in any part of the hydrologic services program regardless of ownership. These stations are specifically defined as:
(1) Forecast Points -- Locations for which the RFC or WSFO/WSO office with an assigned HSA Prepares stage or flood forecasts.
(2) Data Points -- Locations routinely used for data input to RFC or WSFO/WSO HSA forecast procedures.
(3) Special Points -- Locations where flood forecasts are issued in terms of specific crest heights on the gage at the station. These stations are listed in the publication, River Forecasts, by the National Weather Service.
b. Form E-19a should be processed within 60 days when a river station is incorporated into the NWS program.
c. Form E-19a is not required annually.
d. Form E-19a should be changed for significant events, such as the discontinuance of a river stage reporting station (30 days).
*5. Request for Continued Operation of a U.S. Geological Survey (USGS) River Gaging Station. The NWS prepares forecasts for over 2,500 river gaging stations in its river and flood forecasting and water supply forecasting operations. Although a list of these stations has been furnished to the USGS to help insure their operation, conditions may require that the USGS consider discontinuing a station. For example, a station may be partially supported by funds provided by a cooperating Federal or state agency, and the cooperator may propose to withdraw the funding. The USGS has agreed to inform the appropriate NWS regional hydrologist if any of the stations on the list are proposed for discontinuance. The following procedure will be employed in the event that such information is received.
a. The regional headquarters will verify that the station is included in the list of stations used by the NWS.
b. If a station is included in the list, the regional headquarters will attempt to convince the appropriate USGS district office of the need to continue the service.
c. If the negotiation with the USGS district office is unsuccessful, the regional headquarters will prepare a draft letter to the Chief Hydrologist, Water Resources Division, USGS, using the exhibit E-20-3 as a guide, and forward the draft to the Chief, Hydrologic Services Division (HSD), W22.
d. The Chief, HSD, will review the draft, coordinate with the originator (if necessary), type it for the signature of the Associate Director (Hydrology), and forward it to the USGS, Reston, Va.
e. The USGS will use our letter as support for an appeal to continue the funding of the station in question.
Exhibit E-20-3 should be considered as a guide to the appropriate content of the completed letter. The letter must include references to the application of data from the station in question to the forecasting of past flood events, if there are any such records.
If the USGS discontinues a particular river gage, the regional headquarters will review the impact on NWS hydrologic service Operations. The alternatives are to:
a. Shift the forecast point to another river gage nearby.
b. Request the USGS to leave all of their outside gages intact or the NWS will install a river gage at the site and appoint a cooperative observer to take river observations.
c. Discontinue river forecast service at the location and advise local authorities of the discontinued service.
The O/H and regional headquarters will maintain a file of USGS river gaging stations used in NWS operations or those stations required for use in the near future. Changes to the list should be reported to O/H by the regional headquarters to maintain a current file.
*6. Documentation of Flash Flood Alarm Systems. WS Form B-44A,
Report on Substation (Flash Flood Alarm System), Exhibit E-20-4, is designed to record the essential information about flash flood alarm systems. The form will be completed for each existing flash flood alarm system by the RFC flash flood hydrologist responsible for the equipment within 60 days of the commissioning.
When exhibit E-20-4 is reprinted, the item indicated by (1) will be deleted. Also, the item (2) will be changed to read "Sensor Setting (Above Zero of Gage Datum At Site)."
