ALCOM GCP/RAF/277/BEL Aquatic Resource Management for Local Community Development Programme

ALCOM Working Paper No. 18

Database of South African Surface Water Bodies,

source, content and data structure

by

Gayle Johnson GIS and Database Assistant, ALCOM

and

Lieven Verheust Fisheries and Data Management Officer, ALCOM

Funding Agency:

BELGIAN ADMINISTRATION FOR DEVELOPMENT CO-OPERATION

Executing Agency;

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS Harare, 1998

The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.

Johnson, G.; Verheust, L. Database of South African surface water bodies, source, content and data structure. ALCOM Working Paper No 18. Harare, ALCOM/FAO. 1998. 15p.

ABSTRACT

ALCOM has been gathering information on Surface Water Bodies from all mainland countries in the SADC region since 1992. Despite several efforts to get more information, little surface water body data were obtained for South Africa until a mission was undertaken in 1997 to contact different organisations and departments involved in surface water. Several databases on surface water resources were collected and merged into one comprehensive database. This paper describes the procedure for merging, eventual correction of the data and the data structure of the complete South African SWB database, including the metadatabase.

PREFACE

This paper accompanies the digital data on South African surface water bodies as compiled by ALCOM from a set of different databases. It describes the source of the data, compilation procedure, eventual modifications to original data and structure of the database components.

ALCOM is a regional water resource management programme of the FAO (Food and Agriculture Organization of the United Nations). Based in Harare, Zimbabwe, it covers all the mainland member-countries of SADC (Angola, Botswana, Lesotho, Malawi, Mozambique, Namibia, South Africa, Swaziland, Tanzania, Zambia and Zimbabwe).

The aim of ALCOM is to assist member-countries improve the living standards of rural populations through the practice of improved water resource management. Toward this end, pilot activities are conducted in member-countries to demonstrate new techniques, technologies or methodologies.

The information service plays a very important role in ALCOM to disseminate information and to make information available to all those interested in water resource management for local communities. It is in this framework that the following paper was realised.

For more information contact ALCOM at: Mailing address: P.O. Box 3730 Harare, Zimbabwe Physical address: National Parks Complex, Sandringham Drive Harare, Zimbabwe Telephone: 263-4-724985/734797 FAX: 263-4-792782 E-Mail: ALCOM@harare.iafrica.com Homepage: http://www.zamnet.zm/zamnet/alcom/alcom.htm

Cover graphic: point locations of surface water bodies in South Africa

TABLE OF CONTENTS

PREFACE iiLIST OF FIGURES ivLIST OF TABLES ivLIST OF ACRONYMS AND ABBREVIATIONS iv1. INTRODUCTION 12. DATA SOURCES 23. MERGING PROCEDURE 34. CORRECTIONS AND MODIFICATIONS 44.1. CO-ORDINATE PROBLEMS 4 4.1.1. Inverted co-ordinates 4 4.1.2. Location outside the South Africa 44.2. DUPLICATE RECORDS 54.3. CONSTRUCTION DATE 55. RESULTS 55.1. MAIN DATABASE 55.2. POINT DISTRIBUTION FILE IN ATLAS GIS FORMAT 65.3. META-DATABASE 65.4. LIST OF FILES COMPRISING THE COMPLETE SOUTH AFRICAN SWB DATASET 75.5.REFERENCE LISTS OF CORRECTIONS AND MODIFICATIONS 7ANNEX I LIST OF SWBS WITH CO-ORDINATES INVERTED BY ALCOM 10ANNEX II: LIST OF SWBS WITH POSSIBLE WRONG CO-ORDINATES 11ANNEX III: CHARACTERISTICS AND SUMMARY STATISTICS ON THE MAIN DATABASE ZA_SWB.DBF 12ANNEX IV: CHARACTERISTICS AND SUMMARY STATISTICS ON THE MAIN FIELDS IN THE SOURCE DATABASE ZA_SOURC.DBF 14ANNEX V: CODING SCHEME FOR SOURCE DATABASE ZA_SOURC.DBF 16

LIST OF FIGURES

FIGURE 1: Linking of the database files 7FIGURE 2: Distribution of surface water bodies in South Africa 9

LIST OF TABLES

TABLE 1: Number of entries from each information source for 3 important fields 5TABLE 2: Number of SWBs within each drainage region 6

LIST OF ACRONYMS AND ABBREVIATIONS

AGLW Water Resource Development and Management Service ALCOM Aquatic Resource Management for Local Community Development ProgrammeBADC Belgian Agency for Development Cooperation BNA Atlas GIS mapping format DEAT Department of Environmental Affairs and Tourism DSO Dam Safety Office DWAF Department of Water Affairs and Forestry FAO Food and Agriculture Organization of the United Nations ICOLD International Commission On Large Dams IWQS Institute for Water Quality Studies RRSP Regional Remote Sensing Project SADC Southern African Development Community SWB Surface Water Body WRC Water Research Commission WRD Water Resource Database WWW World Wide Web

1. INTRODUCTION

Since 1992, ALCOM has been gathering information on Surface Water Bodies (SWBs) from all countries in the mainland SADC Region. In the past four years this work has evolved from a compilation of a list of dams to what is now probably the most complete and accurate database on all surface water bodies at SADC level and for a number of countries even at national level.

Database fields include geographical, administrative, meteorological, socio-economic, physical and chemical data as well as data on the use of the water body, presence of plant and animal species and fishing activity. Linking to other existing databases with other fields has been made possible by the use of unique identifiers which enables generation of supplementary information.

Since 1996, the SWB database has been integrated in a geographical interface which has enabled a multitude of applications in various disciplines: hydrology, agriculture, fisheries, health, environment or general development. Besides the SWB digital map which holds the point data for all geo-referenced water bodies, the database is now also including polygon data for a number of water bodies.

The South African part of the database has been rather superficial for quite some time and was based on only one list of dams. In 1996 and 97, intensified efforts were undertaken to update the South African SWBs. This resulted in a mission to Pretoria undertaken in September 1997, to contact the different resource institutions on Surface Water at a national level. Several lists and databases were gathered from the Department of Water Affairs and Forestry (DWAF), Department of Environmental Affairs and Tourism (DEAT), and the Water Research Commission (WRC).

The compilation of these lists and databases resulted in a database which holds information on 3843 Surface Water Bodies in South Africa. This document provides information on the data sources, the procedure used to merge the data and the final result of the merging. This includes the identification of errors in the original data sets.

We hope that the present database will not be an end point but both a useful instrument for the end users and an occasion for collaborators to update, correct and supplement the current product.

2. DATA SOURCES

The following institutions provided information which was used to compile the current database. The source for each field is provided in the meta-database so that users can retrace the origin of the data for each separate record and field.

Dam Safety Office (DWAF) List of dams Hardcopy list of dams with a wall height greater than 5m and a capacity greater than 50000 Used data fields: locality number, name, capacity, river name, nearest town, distance from nearest town, wall length, wall height, co-ordinates, surface area, construction date Date: printed September 18, 1997 Contact person: Mr. Allan Chemaly, chief engineer

Hydrographical Survey Service (DWAF) List of dams Hardcopy list of dams

Used data fields: locality number, name, river name, co-ordinates, nearest town, province, owner, construction/survey date, catchment area, capacity Date: September 12, 1997 Contact person: Ms. Janet Clark

Hydrology Service (DWAF) List of government SWBs, both natural and man-made Hardcopy list Used data fields: hydro number, name, place name, co-ordinates, drainage region, catchment area, capacity, surface area Date: 1996 Contact person: Mr. Johan Wentzel, assistant director

Institute of Water Quality Studies (IWQS, DWAF) List of water bodies with water quality data Data fields: station number and physical/chemical data such as pH, alkalinity and conductivity, only pH and conductivity records were used Digital data in DBF format Date: August 1997 Contact person: Mr. Mike Silberbauer, specialist scientist

Department of Environmental Affairs and Tourism (DEAT) 'Wetlands of South Africa', SA Wetlands Conservation Programme Series, Edited by G.I. Cowan, 1995 Publication which includes list of wetlands in South Africa Used data fields: name, co-ordinates, surface area, maximum depth, comments (shoreline length and sea connection) Date: 1995 Contact person: Mr. Geoff Cowan

Water Research Commission (WRC) WR90- Surface Water Resources of South Africa Digital data (CD-ROM) including a list of dams in DBF format Data fields: area, perimeter, dsm, dam reg. id, catnum, dam no., name, capacity, river, town, date, farm name, height, type, co-ordinates, sizec, hazard, class, surface area Date: 1990 Contact person: Mr. Hugo Maaren

Water Resources, Development and Management Service (AGLW/FAO Rome) Geo-referenced database on large African dams The basic reference for this data base was the World register of large dams, prepared by ICOLD. Additional information for South Africa was most likely based on the book "Management of the Water Resources of the Republic of South Africa", DWAF, 1986 Digital data in Excel format Used Data Fields: country, name, river, nearest city, province/state, year of completion, height, capacity, area, co-ordinates Date: June 1996 Contact person: Mr. Jean-Marc Faures

3. MERGING PROCEDURE

The following steps were executed to merge data from the different sources. The hardcopy list of dams from the Dam Safety Office was used as a base file since it was the largest inventory with 3592 dams, and according to the originators also one of the most reliable ones.

1. All the records from the Dam Safety Office (DSO) were scanned into text files. These were edited first in a word processor, by inserting tabs to define field separations and then imported as tab delimited files in a spreadsheet. Further editing was done to ensure entries appeared in the correct fields and an attempt was made to correct spelling errors caused by the scanning process. Some of these may still exist.

2. A database file was created from the DSO spreadsheet file and this was used as the base file to check which records still needed to be added to the existing inventory from AGLW/FAO. A manual search was done first using data from the DWAF Hydrological Service (government records) and a number of the smaller dams were added. This also included some natural water bodies such as Nsezi lake.

3. A third search was manually carried out using records from the DWAF Hydrographical Survey Service. There were few outstanding data and these were added to the base file.

4. A list of South African isolated coastal lakes and coastal lake systems was taken from a report published by the Department of Environmental Affairs and Tourism, 'Wetlands of South Africa', SA Wetlands Conservation Programme Series, 1995. The majority of these records were new and were added to the existing inventory. Where the records already existed, for example from the DWAF Hydrological Service, the records were merged and the various sources recorded.

5. The newly created database (steps 1-4) was linked to the existing older database (mainly from AGLW/FAO), first based on co-ordinates (latitude, longitude) and then by using names. Where there were duplicate records the data entries were merged to preserve all the data from the various fields. Where there were discrepancies, data from the DSO was given priority, except in the instance where co-ordinates from another source were more precise. A small number of dams in the old database were not present in the new one and these were added accordingly.

6. Hydrozones were derived from the index number. The first number and letter of the index figure was taken to be the hydrozone at the primary level.

SADC Identifiers (unique identifiers used in the complete SADC SWB database) are added as sequential numbers according to the time of entry in the database. This results in lower ID's for the water bodies that were already present in the original older database. The locality number was entered as the national index number and as a unique national identifier.

4. CORRECTIONS AND MODIFICATIONS

After merging of the databases, entries were checked again for obvious mistakes and corrected accordingly. Most obvious mistakes were found in relation with co-ordinates and construction date. Related to the coordinate problem is the occurrence of duplicate locations for apparently different water bodies.

4.1. Co-ordinate problems

4.1.1. Inverted co-ordinates

A co-ordinate file of the SWBs was created and overlayed with the South African country border and hydrological zones. A number of SWBs were located outside of the country border. Many of these were located on the map in Mozambique while they should have been in Cape Province. It appeared that latitude and longitude of these co-ordinates had been inverted. These coordinates were subsequently interchanged by ALCOM, providing this located the water body in the correct drainage region. The above leads to the possibility of further undetected instances of inverted co-ordinates especially in the 30 degrees latitude and 30 degrees longitude zone. A list of SWBs with inverted co-ordinates is provided in annex I. 4.1.2. Location outside the South Africa

A number of SWBs that were plotted outside of South Africa's borders did not appear to have inverted co-ordinates, indicating wrong latitude or longitude figures. This also leads to the possibility of other SWBs having wrong co-ordinates which are less conspicuous due to the nature of their plotted location. It was noted that several SWB points were plotted in Lesotho which should have been plotted in Harrismith. SWBs were plotted region by region and where it was noticed that SWBs were wrongly located, the co-ordinates were removed from the co-ordinate field and placed in the comments field where they would be easily accessible for further examination. There still remains some work to be done in identifying SWBs with wrong co-ordinates, especially within the drainage regions at the secondary and tertiary levels. A list of SWBs with possible wrong co-ordinates is provided in annex II. 4.2. Duplicate records A special search was done to find duplicate records in the database, based on SADC_ID, NAT_ID (national identifier) and NAT_INDEX (national index number). In the event of two very similar records with minor differences in several fields, but one major difference, the records were entered uniquely. An additional entry was made in the DUPE_ID (duplicate identifier) field should a query arise at a further stage as to their similarity.

Records with the same latitude and longitude could not be considered necessarily as duplicate record due to the precision of coordinates. It happens quite often that two water bodies (e.g. in the case of a silt-trap dam) are situated so close to each other that there is no difference in coordinates to the nearest minute. A list of SWBs with the same co-ordinates as at least one other SWB is provided in a separate file (za_check.dbf).

4.3. Construction date Impossible construction dates such as 1147 were changed to 1947 when indications existed about the right date. 5. RESULTS

5.1. Main database The total number of dams resulting from the merger equalled 3843, of which 3397 have surface areas, 3713 have capacity data and 3767 have co-ordinates (cf. table 1). Data from AGLW/FAO did not have any surface areas. No capacity figures were available from the DEAT publication because this concerned natural water bodies. More than 93%

of all records were extracted from the Dam Safety Record data-set which were in some cases supplemented with information from the Institute for Water Quality Studies. Table 1: Number of entries from each information source for 3 important data fields Main Sources No. of entries

with known co-ordinates

No. of entries with known

surface areas

No. of entries with known capacities

Total No.of entries

AGLW/FAO Rome 25 0 21 28 Dam Safety Office (DWAF) 3518 3343 3546 3583 Hydrographical Survey Service (DWAF) 142 1 125 148 Hydrology Service (DWAF) 44 21 21 45 Dept. Environ. Affairs & Tourism 38 32 0 39 Total 3767 3397 3713 3843

All co-ordinates from the DSO, Hydrographical Survey Service and AGLW/FAO Rome were obtained in degrees and minutes only (no seconds). As a result, accuracy may become a problem at a better scale. Where possible, as in the case of data from the Institute of Water Quality Studies, water bodies were linked to a database with more precise coordinates which were included in the database. Although data from the WR90 were used for cross-checking (specifically with regard to the hydrozones), none of the dams from the WR90 CD were integrated in the database. This is due to the fact that it was not possible to get details on the source of surface area and capacity data which looked unrealistic. A complete list of the data fields and summary statistics is given in annex III and available on disk (za_swb.dbf) Table 2: Number of SWBs within each drainage region

Drainage Region

Number with co-ordinates Total

A 237 241 B 251 260 C 377 383 D 322 327 E 211 215 F 1 1 G 439 443 H 277 282 J 115 118 K 90 92 L 104 104 M 6 6 N 41 41 P 56 56 Q 97 100 R 52 55 S 63 63 T 118 123 U 332 342 V 227 231 W 139 143 X 159 161

5.2. Point distribution file in Atlas GIS format A point distribution file (za_swb.bna) was created in atlas GIS format based on the coordinates in the database. The point distribution file holds two identifiers for each point: the unique identifier in the database (SADC_ID) and the name of the water body. The co-ordinate file was overlayed with the drainage regions of South Africa using a mapping programme (Mapviewer), to produce a distribution map of SWBs in South Africa (figure 2).

5.3. Meta-database The meta-database holds information on the source of each field and each record in the main database. The main meta-database (za_sourc.dbf) is basically a copy of the SWB database with data replaced by a source identifier. This source identifier can be linked to the source code database (za_code.dbf) which holds the exact information on each source (cf. annex V). The source identifying numbers are not logically sequenced as they were derived from the larger source file which was created for the complete SADC SWB database holding almost 20000 records.

5.4. List of flies comprising the complete South African SWB dataset Following files comprise the complete SWB dataset:

za_swb.dbf main database with 3848 SWB records in South Africa za_sourc.dbf main source file comprising source codes for each entry za_code.dbf meta-database source code file (cf. annex V) za_swb.bna point atlas GIS file of SWBs in South Africa with co-ordinates

Characteristics of data fields and summary statistics on za_swb.dbf and za_sourc.dbf are provided in annex III and IV. The files can be linked in a regular database package using the SADC identifier so that a source code appears behind every entry. It follows that the coding file should be linked to define the numeric source code (cf. figure 1).

Figure 1: Linking of the database files

5.5. Reference lists of corrections and modifications All corrections and modifications that were made by ALCOM to the original data are documented in annex and available in the following files:

annex l.dbf list of SWBs with co-ordinates interchanged by ALCOM (Annex I) annex2.dbf list of SWBs with possible wrong co-ordinates (Annex II) za_check.dbf list of SWBs with duplicate set of coordinates

Figure 2: Distribution of Surface Water Bodies in South Africa

ANNEX I: LIST OF SWBS WITH CO-ORDINATES INVERTED BY ALCOM

(latitude and longitude interchanged)

SADC_ID Index number 17760 J112-13 16919 E200-12 17593 H300-16 17187 G102-95 17114 G101-BZ 17202 G104-AL 17303 G204-AX 17103 G101-BM 17476 G403-59 17474 G403-54 17475 G403-57

ANNEX II: LIST OF SWBS WITH POSSIBLE WRONG CO-ORDINATES

Region SADC_ID Index_no

A 15807 A231-26

A 15948 A801-13

A 15897 A601-34

A 13741 A701-39

A 13491 A300-03

A 13744 A300-05

B 16184 B801-80

B 16175 B801-70

B 16190 B801-91

B 16040 B200-10

B 16010 B102-51

B 13545 B800-25

B 13757 B500-08

B 13578 B500-07

B 13438 B500-03

B 13474 B700-09

B 13613 B600-04

B 16092 B401-45

B 13568 B100-13

B 19398 B4R003

C 13712 C520-13

C 13661 C510-26

C 13666 C250-10

C 16545 C805-41

C 16529 C809-43

C 16526 CB01-39

C 16525 C801-38

C 13328 C110-13

C 13677 C220-01

D 16755 D341-07

D 16667 D201-67

D 13808 D200-20

D 13598 D200-16

D 13547 D200-14

D 13425 D200-12

D 13413 D200-11

D 13743 D200-10

D 13314 D200-04

D 16683 D202-60

D 13697 D350-09

D 13417 D350-06

E 13372 E201-AL

E 17046 E202-16

E 13364 E400-01

E 17054 E204-15

E 13786 E200-06

E 13577 E200-03

E 13784 E100-06

E 13703 E100-05

E 16896 E100-66

G 13498 G430-01

G 13458 G200-09

G 13385 G200-08

G 17464 G402-60

G 17188 G102-96

H 13552 H100-21

H 13700 H100-17

H 13646 H100-15

H 13416 H100-05

J 13428 J210-01

J 17796 J220-01

J 13816 J400-02

J 13647 J120-04

J 13324 J120-02

J 17855 J350-12

J 13427 J120-03

J 17756 J111-06

J 13390 J220-02

J 13718 J210-02

K 13724 K300-04

K 15684 K4R001

M 13765 M200-01

M 13686 M100-03

M 13360 M100-02

M 13443 M100-01

N 13617 N140-18

N 13334 N110-01

N 13699 N400-03

P 13466 P300-01

P 13574 P100-03

P 13473 P100-02

P 13693 P300-02

Q 13691 Q140-03

Q 13573 Q140-02

Q 13505 Q110-03

Q 13461 Q110-02

Q 13351 Q120-03

Q 18199 Q910-10

Q 13483 Q940-01

R 13593 R300-01

R 18289 R303-17

R 18288 R303-16

R 18279 R302-12

S 13812 S100-01

S 13448 S600-04

S 13487 S300-08

T 18360 T300-01

T 18431 T501-28

T 18421 T501-18

T 18454 T501-58

T 18403 T401-01

T 13589 T300-04

U 18760 U402-16

U 18796 U601-41

U 18732 U401-18

U 18834 U700-27

U 18813 U601-69

U 18479 U100-08

U 18486 U100-18

U 13745 U700-08

U 13727 U300-03

U 13457 U300-01

U 13592 U200-10

U 13604 U500-01

U 13564 U400-03

U 13408 U400-02

U 18537 U201-AK

U 18622 U201-98

U 18765 U500-04

V 18896 V104-37

V 13486 V100-20

V 13488 V100-18

V 13648 V100-10

V 13472 V100-08

V 19008 V202-28

V 18949 V201-36

V 19019 V202-72

W 19139 W211-22

W 19180 W303-19

W 19103 W110-12

W 19109 W110-18

W 13476 W530-03

X 19232 X100-04

X 19305 X201-75

X 13706 X200-24

ANNEX III: CHARACTERISTICS AND SUMMARY STATISTICS ON THE MAIN DATABASE ZA_SWB.DBF

Field name Field description Unit Type of data

Column Width

Count non

blank

Maximum Minimum Average Total

SADC ID SADC Database Identification Number Label 6 3843 Nat ID National Database Identification Number Value 6 3843 Nat Index Index in national database (if applicable) Label 8 3788 Name Name of the water body Label 40 3843 Latitude Latitude (in decimal degrees) dec deg Value 8 3767 -22.20 -34.73 -30 Longitude Longitude (in decimal degrees) dec deg Value 7 3767 32.87 17.63 26 Grid_ Ref Map grid reference Label 6 0 Map_Nr Map number Label 6 0 Coord_South Coordinates south (in any format) dms Label 10 381 Coord_East Coordinates east (in any format) dms Label 10 381 UTM_Zone UTM zone number Value 6 0 UTM_Coord UTM coordinates Label 6 0 Rivername Name of the main river(s) which feed(s) the

water body Label 22 3492

Sub-catchment Name of the sub-catchment Label 6 0 Main catchment

Name of the main stream catchment Label 6 0

Division Division in which the water body is situated (if applicable)

Label 6 0

District District in which the water body is situated Label 6 0 Province Province or Region in which the water body is

situated Label 6 518

Country Country in which the water body is situated Label 2 3843 International Is the water body shared by different countries? Label 6 0 Owner Unit which controls the water body or name of

owner Label 6 143

Ownertype Type of ownership Label 6 0 Surf. area Full supply surface area ha Value 8 3397 41700 0.10 80 386258.6 Capacity Full supply capacity m3 Value 12 3713 5673778000 5000.00 1004047337280277600Maxdept Maximum depth m Value 6 30 1607 2.00 61

Mean depth Mean depth m Value 6 0 Catch. area Catchment area of the water body km2 Value 8 131 79903.00 1.00 2085 273126 pH Average pH value of surface water pH Value 5 228 9.00 4.70 8 Conductivity Average conductivity of surface water μS Value 5 210 35177.00 -9.00 792 Transparency Average Secchi Disk value cm Value 6 22 4.00 1.00 3 Permanence Is the water body permanent or seasonal? Label 6 0 Solltype Main soil type of the catchment of the reservoir FAO Label 6 0 Type Type of water body (Lake, Swamp or Reservoir) Label 1 539 Constr_Yr Construction year of the dam YYYY Value A 3404 1997 1800 1972 Wallheight Height of the dam wall m Value 4 3578 93 3.00 11 Condition Dam wall condition Label 6 0 Siltation % Estimated percentage of dam siltation (volume

%) % Value 6 430 70.00 1.00 3

Fenced Is the damwall fenced ? Label 6 0 Access Access by road Label 6 0 Dist.vill Distance from the nearest village km Value 5 3581 190.00 0 19 Main use Main use of the water body Value 1 0 Domestic Is the water body used for domestic water

supply? Label 1 0

Irrigation Is the water body used for irrigation? Label 1 168 Livestock Is the water body used for livestock watering? Label 1 0 Municipal water

Is the water body used for municipal water supply?

Label 1 93

Bricks Is the water body used for brick construction? Label 1 2 Industry Is the water body used for industrial purposes? Label 1 4 Fishing Is the water body used for fishing? Label 1 0 Other use Any other use of the water body? Label 6 0 Crocs Presence of crocodiles Label 1 0 Hyacinth Presence of water hyacinth (Eichornia

crassipes) Label 1 0

Hook and line Presence of hook and line fishing Label 1 0 Traps Presence of trap fishing Label 1 0 Sport Presence of sport fishing Label 1 0 Gill net Presence of gill net fishing Label 1 0 Seine nets Presence of seine net fishing Label 1 0

Fisherfolk Number of net fishers Value 6 0 Nets Number of gill nets used (1 net = 100m2

mounted) Value 6 0

Boats Number of boats/canoes/vessels Value 6 0 Catch/yr Total yearly fish catch Value 6 0 Comments Any observations or comments on data

collection or water body Label 109 122

Source of data Source of Data Label 80 3843 Orig_ID ID in original database Value 6 493 Orig_Ref Reference source in original database Label 6 493 Dupe_ID SADC ID of possible duplicate record Label 6 8 Main_ID SADC ID of water body where this water body

belongs to Label 6 0

Hydro number Hydro Number Label 7 58 Hydrozone Hydrozone Label 3 3787 Subzone Subzone Label 6 0 Drainage region

Drainage Region Label 4 67

Locality Locality Label 29 3774 Reliability Reliability of Source data Label 9 0

ANNEX IV: CHARACTERISTICS AND SUMMARY STATISTICS ON THE MAIN FIELDS IN THE SOURCE DATABASE ZA_SOURC.DBF

Field name Field description Type of data

Column Width

Count non blank

SADC ID Source code for SADC Database Identification Number Label 6 3843

Nat ID Source code for National Database Identification Number Label 2 3843

Nat Index Source code for Index in national database (if applicable) Label 2 3786

Name Source code for Name of the water body Label 2 3843

Latitude Source code for Latitude (in decimal degrees) Label 2 3767

Longitude Source code for Longitude (in decimal degrees) Label 2 3767

Grid_Ref Source code for Map grid reference Label 2 0

Map_Nr Source code for Map number Label 2 0

Coord_South Source code for Coordinates south (in any format) Label 2 381

Coord_East Source code for Coordinates east (in any format) Label 2 381

UTM_Zone Source code for UTM zone number Label 2 0

UTM_Coord Source code for UTM coordinates Label 2 0

Rivername Source code for Name of the main river(s) which feed(s) the water body Label 2 3492

Sub-catchment Source code for Name of the sub-catchment Label 2 0

Main catchment Source code for Name of the main stream catchment Label 2 0

Division Source code for Division in which the water body is situated (if applicable) Label 2 0

District Source code for District in which the water body is situated Label 2 0

Province Source code for Province or Region in which the water body is situated Label 2 518

Country Source code for Country in which the water body is situated Label 2 3843

International Source code for is the water body shared by different countries? Label 2 0

Owner Source code for Unit which controls the water body or name of owner Label 2 143

Ownertype Source code for Type of ownership Label 2 0

Surf. area Source code for Full supply surface area Label 2 3397

Capacity Source code for Full supply capacity Label 2 3713

Maxdept Source code for Maximum depth Label 2 30

Meandepth Source code for Mean depth Label 2 0

Catch. area Source code for Catchment area of the water body Label 2 131

pH Source code for Average pH value of surface water Label 2 228

Conductivity Source code for Average conductivity of surface water Label 2 210

Transparency Source code for Average Secchi Disk value Label 2 22

Permanence Source code for Is the water body permanent of seasonal? Label 2 0

Soiltype Source code for Main soil type of the catchment of the reservoir Label 2 0

Type Source code for Type of water body (Lake, Swamp or Reservoir) Label 2 539

Constr_Yr Source code for Construction year of the dam Label 2 3404

Wallheight Source code for Height of the dam wall Label 2 3578

Condition Source code for Dam wall condition Label 2 0

Siltation % Source code for Estimated percentage of dam silation (volume %) Label 2 480

Fenced Source code for is the damwall fenced ? Label 2 0

Access Source code for Access by road Label 2 0

Dist.vill Source code for Distance from the nearest village Label 2 3581

Main use Source code for Main use of the water body Label 2 0

Domestic Source code for is the water body used For domestic water supply? Label 2 0

Irrigation Source code for Is the water body used for irrigation? Label 2 168

Livestock Source code for is the water body used for livestock watering? Label 2 0

Municipal water Source code for is the water body used for municipal water supply? Label 2 93

Bricks Source code for is the water body used for brick construction? Label 2 2

Industry Source code for Is the water body used for industrial purposes? Label 2 4

Fishing Source code for Is the water body used for fishing? Label 2 0

Other use Source code for Any other use of the water body? Label 2 0

Crocs Source code for Presence of crocodiles Label 2 0

Hyacinth Source code for Presence of water hyacinth (Eichornia crassipes) Label 2 0

Hook and line Source code for Presence of hook and line fishing Label 2 0

Traps Source code for Presence of trap fishing Label 2 0

Sport Source code for Presence of sport fishing Label 2 0

Gill net Source code for Presence of gill net fishing Label 2 0

Seine nets Source code for Presence of seine net fishing Label 2 0

Fisherfolk Source code for Number of net fishers Label 2 0

Nets Source code for Number of gill nets used (1 net = 100m2 mounted) Label 2 0

Boats Source code for Number of boats/canoes/vessels Label 2 0

Catch/yr Source code for Total yearly fish catch Label 2 0

Comments Source code for Any observations or comments on data collection or water body Label 2 122

Source of data Source code for Source of Data Label 80 3843

Orig_ID Source code for ID in original database Label 2 493

Orig_Ref Source code for Reference source in original database Label 2 493

Dupe_ID Source code for SADC ID of possible duplicate record Label 2 8

Main_ID Source code for SADC ID of water body where this water body belongs to Label 2 0

Hydro number Source code for Hydro Number Label 2 58

Hydrozone Source code for Hydrozone Label 2 3787

Subzone Source code for Subzone Label 2 0

Drainage region Source code for Drainage Region Label 2 67

Locality Source code for Locality Label 2 3774

Reliability Source code for Reliability of Source data Label 2 0

ANNEX V: CODING SCHEME FOR SOURCE DATABASE ZA_SOURC.DBF

Source ID

Year Source Media Type Info Information provided

12 1996 World Register of large dams , prepared by ICOLD XLS file database Geo-referenced data base on African dams 22 1997 Institute Water Quality Studies(Directorate of Hydrology),

Dept. Water Affairs & Forestry DBF file database SWS coordinates, physical-chemical data

24 1995 Wetlands of South Africa, SA Wetlands Conservation Programme, Dept. Env. Affairs and Tourism

hardcopy book Location, morphometrics & related details of SA's isolated coastal takes and coastal take systems

25 1997 Dam Safely Office (DWAF) hardcopy paper List of registered dams in South Africa 26 1997 Hydrographical Survey Service (DWAF) hardcopy paper List of surveyed dams 27 1997 Hydrology Service (DWAF) hardcopy paper List of government registered dams 29 1998 Revised by ALCOM in January 1998