Guidelines for Groundwater Abstraction Surveys

GUIDELINES FOR GROUND WATER ABSTRACTION SURVEYS WATER RESOURCES AUTHORITY September 2019 i Guidelines for Groundwater Abstraction Surveys in Kenya TABLE OF CONTENTS 1. INTRODUCTION ............................................................................................................2 1.1 Background Information .............................................................................................2 1.2 Purpose of these Guidelines ........................................................................................3 1.3 How to use these Guidelines .......................................................................................3 2. GROUNDWATER ABSTRACTION SURVEY PROTOCOL ...................................4 2.1 Objectives ...................................................................................................................4 2.2 Groundwater Abstraction Points .................................................................................4 2.2.1 Springs ............................................................................................................4 2.2.2 Shallow wells ..................................................................................................5 2.2.3 Boreholes ........................................................................................................6 2.3 General Description of Activities in Planning Phase for an Abstraction Survey .......6 2.3.1 Coordination and Collaboration Arrangements ..............................................7 2.3.2 Scheduling of Abstraction Survey ..................................................................7 2.3.3 Public Notification ..........................................................................................8 2.4 Fieldwork Preparations ...............................................................................................8 2.4.1 Desk Review ...................................................................................................8 2.4.2 Reconnaissance Survey ...................................................................................9 2.4.3 Composition of Field Teams .........................................................................10 2.4.4 Training Field Teams ....................................................................................10 2.4.5 Equipment .....................................................................................................10 2.4.6 Health and Safety ..........................................................................................11 2.5 Fieldwork ..................................................................................................................11 2.6 Data and Record Management ..................................................................................12 2.6.1 Data Collection Forms and ODK ..................................................................12 2.6.2 Records Management....................................................................................12 2.7 Quality Control and Quality Assurance ....................................................................13 2.7.1 Flow Meter Quality Control and Quality Assurance ....................................13 2.7.2 Flow Meter Manufacture Specifications .......................................................13 3. ABSTRACTION MEASUREMENT METHODS ......................................................14 3.1 Internal/Online Flow Meter ......................................................................................14 3.2 External Flow Meter .................................................................................................14 3.3 Measured Volume over Recorded Time ...................................................................15 3.4 Calibrated Weirs .......................................................................................................15 3.5 Estimating Water Abstraction ...................................................................................16 3.5.1 Estimate based on irrigated area ...................................................................16 3.5.2 Estimate based on pump curves ....................................................................18 3.5.3 Estimate based on electrical power bill ........................................................18 3.5.4 Estimate Using Population Served................................................................18 4. DATA ANALYSIS AND REPORTING ......................................................................19 4.1 Objectives .................................................................................................................19 4.2 Data Analysis – Groundwater Abstraction ...............................................................19 ii Guidelines for Groundwater Abstraction Surveys in Kenya 4.3 Data Analysis – Permit Compliance .........................................................................19 4.4 Mapping ....................................................................................................................19 4.5 Reporting and Stakeholder Presentation ...................................................................19 4.5.1 Discussion Points ..........................................................................................19 4.5.2 Deliverables ..................................................................................................20 List of Tables Table 2-1: Equipment List for Groundwater Abstraction Surveys .......................................... 10 Table 3-1: Discharge Coefficients for a V-Notch Weir ........................................................... 16 List of Figures Figure 2-1 : Protected Springs; Kwale (left), Kisii (right) ......................................................... 5 Figure 2-3: An unprotected well ................................................................................................ 5 Figure 2-4: A protected well ...................................................................................................... 5 Figure 2-5: Nairobi BH Census: Consolata Sisters (left), Public Service Club (right) ............. 6 Figure 4-1 Micronics PF220 Flow Meter ............................................................................... 28 Figure 4-2: Shenitch Stuff 300 Flow Meter ............................................................................. 29 List of Appendices Appendix 1: GW Abstraction Survey Form Appendix 2: GW Permit Compliance Checklist Appendix 3: Sample Newspaper Advertisement Appendix 4: Instructions for use for selected Flow Meters Appendix 5: Groundwater Surveys – Some Theoretical Examples i Guidelines for Groundwater Abstraction Surveys in Kenya ABBREVIATIONS ASAL Arid and Semi Arid Lands BH Borehole GPS Global Positioning System GW Ground Water ODK Open Data Kit QA Quality Assurance QC Quality Control WAP Water Allocation Plan WRA Water Resources Authority WRUA Water Resources User Association 2 Guidelines for Groundwater Abstraction Surveys in Kenya 1. INTRODUCTION 1.1 Background Information Water resources management involves activities of management, control and regulation of water resources to ensure sustainable use and development of water resources to meet basic human needs, the needs of the environment, economic development, water security and alleviate water use conflicts. The Water Act 2016 mandates the Water Resource Authority (WRA) to regulate the management and use of water resources. The Act Section 12(a) tasks the Authority with the responsibility to develop “principles, guidelines, and procedures for the allocation of water resources”. Water allocation planning is based on a comprehensive water resources allocation framework that takes into account social, economic and environmental considerations for the sustainable utilisation of water resources. This is particularly crucial in many parts of Kenya where water is scarce and thus requires fair and transparent allocation to manage ever-increasing demands on the limited resources. The Authority’s Water Allocation Plans bring into effect provisions of the National Water Resources Management Strategy, the National Water Master Plan 2030, respective Catchment Management Strategies and Sub-Catchment Management Plans, as well as the Water Resource Management Rules (2007) to ensure that water resources are shared in compliance with the law. To aid the Authority fulfil its mandate Guidelines for Water Allocation have been developed as a tool relevant to the business of formulating and enforcing procedures and processing water permit applications. The water abstraction and pollution surveys for both surface and groundwater are important precursors to the development of a water allocation plan. In addition, the abstraction and pollution surveys can be undertaken independently of a WAP development process to inform WRA and stakeholders regarding: • Actual water use; • Status of existing authorisations; • Compliance to existing authorisations; • Water quality; • Point and non-point pollution sources; • Aquifer status. These Guidelines focus on conducting groundwater abstraction surveys. There will be instances when a groundwater abstraction survey or hydrocensus is required. This may be in the context of a hydrocensus supporting a private-sector Hydrogeological Survey Report; or an Authority-led study in pursuit of a Water Allocation Plan or an Aquifer Management Plan. This guideline thus describes the various approaches that can be adopted. 3 Guidelines for Groundwater Abstraction Surveys in Kenya 1.2 Purpose of these Guidelines This document sets out technical guidelines for conducting groundwater abstraction surveys. The document is intended to be a technical reference document for the planning, fieldwork preparation, fieldwork, data analysis and reporting and is developed to provide guidance and propose best practice for conducting groundwater abstraction surveys. Within this context, this document: 1. Gives guidance on planning and preparation for the exercise; 2. Gives suggestions and advice to ensure safety during fieldwork; 3. Recommends procedures to be followed in conducting abstraction surveys; 4. Recommends methods of data analysis and format for presentation of results; 5. Gives suggestions to choice and use of equipment in abstraction measurements; 6. Provides basic skills in equipment handling and calibration. It is expected that the guidelines will contribute towards ensuring that all groundwater abstraction surveys are conducted following a set standard of procedure and that the data collected are analysed and results presented in standardized format. 1.3 How to use these Guidelines This Guideline is to be used alongside the Groundwater Water Quality Survey Guidelines and the Guidelines for the Development of a Water Allocation Plan. The Guidelines follow a work flow process as follows: • Chapter 2 describes the planning phase, preparation phase and the fieldwork phase with procedure of conducting a ground water abstraction survey and data management; • Chapter 3 provides guidelines on various methodologies for abstraction measurement, depending on the abstraction point and the available technologies; • Chapter 4 provides guidelines for consistent and thorough data analysis to extract and present key findings for contribution to a water allocation plan. In the Appendices are a newspaper advertisement, data collection forms and instruction for use for selected flow meters. Appendix 5 presents some theoretical examples of groundwater surveys. 4 Guidelines for Groundwater Abstraction Surveys in Kenya 2. GROUNDWATER ABSTRACTION SURVEY PROTOCOL This section describes approaches to conducting groundwater abstraction surveys, and attempts to address all likely scenarios that may be encountered in the field. 2.1 Objectives Water resources are allocated to various users/uses by the Water Resources Authority (WRA) through a permitting system to maintain sustainable abstraction from water resources. The purpose of an abstraction survey is to capture information on actual abstraction of a water resource to inform allocation and enforcement decisions in subsequent development of a Water Allocation Plan (WAP) to achieve sustainable water use. The need for an abstraction survey may be driven by various motives such as water use conflicts or emerging tendencies of over-abstraction. An abstraction survey is also required as a precursor in the development of a Water Allocation Plan. The approach adopted for an abstraction survey is as follows: • Practical: Data collection process should be clear, practical and complete; • Safe: During fieldwork, ensure adherence to safety rules and regulations; • Collaborative: Ensure involvement of the WRA and WRUAs to establish credibility during the field work, provide local knowledge, and to encourage an understanding of the importance of water management. The objectives of a groundwater abstraction survey partly depends on context, but in all cases the ultimate objective is to collect spatial, water use and abstraction data related to groundwater resources. 2.2 Groundwater Abstraction Points Groundwater can be abstracted through springs, shallow wells or boreholes. 2.2.1 Springs In parts of the country where springs are common they form an important component in domestic and rural water supply. Many springs are protected. Figure 2-1 shows two examples. Springs are typically easy to enumerate and usually easy to measure discharge from. However, some very large springs – such as Njoro Kubwa, Mzima or Kikuyu – have discharge rates that require flow gauging, or a measuring weir to record discharge from. With such springs, abstraction is usually via pipework, with or without a flow meter. Springs should always be treated as groundwaters. There are situations where surface water features that are considered ‘surface water’ are actually groundwater features (an obvious example is ‘surface water’ at Kibwezi; this is exclusively groundwater except for periods after rains. In the same way, the bulk of the water in the Tsavo River is groundwater, until it joins 5 Guidelines for Groundwater Abstraction Surveys in Kenya the Athi, and other than after rains). Other examples are the significant stream arising from Mayer’s Spring at Ewaso Kedong in the Rift Valley; and the streams due to the Njoro Kubwa and associated springs in Taveta. While they may be treated as surface water resources for the purposes of a WAP (indeed, they are the only type of groundwater that can be treated as a surface water for WAP purposes, because measurable flows allow the calculation of Q95 if the flow data exist), it must be borne in mind that they are truly groundwaters most of the time. Figure 2-1 : Protected Springs; Kwale (left), Kisii (right) 2.2.2 Shallow wells Shallow wells are widespread across Kenya and occur in almost all geologies and all counties. They are usually easy to find and enumerate, particularly in rural contexts however, shallow wells in some urban settings are more problematic (e.g. urban Wajir). They range from temporary ‘scrapes’ in sand rivers used by pastoralists to permanent protected wells fitted with handpumps or mechanical pumps as illustrated in Figure 2-2 and Figure 2-3 below:- Figure 2-2: An unprotected well Figure 2-3: A protected well 6 Guidelines for Groundwater Abstraction Surveys in Kenya 2.2.3 Boreholes Boreholes (BHs) are widely used across Kenya for private and commercial uses, public water supply and irrigation. They are usually relatively easy to find in rural and ASAL areas, but in urban areas are often difficult to find without local knowledge. During the 2010-2011 Nairobi BH Census, a total of 376 possible BHs were not enumerated due to denials or land owner hostility. Similar problems are likely in other areas of Kenya, and not just urban areas. Boreholes should (though not always are) be fitted with flow meters (with the exception of handpump-equipped boreholes). In cases where they are absent, abstraction should be measured or estimated using the methods described in this Manual. Figure 2-4 below shows two of the BHs captured during the Nairobi BH Census. Figure 2-4: Nairobi BH Census: Consolata Sisters (left), Public Service Club (right) 2.3 General Description of Activities in Planning Phase for an Abstraction Survey Groundwater abstraction surveys or hydrocensus exercises aim to capture geo-reference, water use and abstraction data. In a given area you may encounter a combination of springs, shallow wells and boreholes while in other areas groundwater use may be restricted to only shallow wells (as in some ASAL areas), or only boreholes (central Nairobi). In all field surveys, there are several steps that are followed irrespective of survey type: 1. Framing the need for a survey. Why is a survey needed? What is the objective of the survey? A survey might be initiated after a noticeable increase in Applications for Authorisations for boreholes in a given area is observed, or if a major project (for example a large urban wellfield) is planned in a given area, the impact on existing groundwater users may need to be evaluated prior to committing to the project. 2. Inception phase. Involves framing the scope, area and nature of the survey. If necessary, carry out a reconnaissance visit to help frame the scope and area. 3. Plan the survey. Planning will often involve a training component, so all staff involved know the methods and techniques they will use. The relevant WRUA(s) will be informed and if desirable, involved in the planning process. Planning will usually include a public notice in a newspaper, informing the public that the survey will be carried out, stating why 7 Guidelines for Groundwater Abstraction Surveys in Kenya it is needed, the approximate area to be covered and the dates across which the survey will take place. The planning process may be described in a Field Preparation Report. 4. If necessary, customise survey forms. Standard forms are presented in Appendix 1 (Abstraction Survey) and Appendix 2 (Permit Compliance). 5. Carry out the survey. If the survey is very large (covering a large area, or expected to take a long time), then periodic progress reporting may be desirable. 6. Data analysis and interpretation. This involves developing and then populating a database to analyse and interpret data, generating maps showing what was found and where, and reaching conclusions and recommendations. 7. Reporting and dissemination. In most cases, policymakers, regulators and the public will need to know what the outcome of the survey was. A Final Report will be prepared, and Stakeholder Workshops held. Feedback should be sought from stakeholders. 2.3.1 Coordination and Collaboration Arrangements An abstraction survey requires the following elements: • Social acceptance; • Technical competence; and • Legal authority. Undertaking groundwater abstraction surveys can be physically demanding, in some cases exposing field team members to risks from: • Violence or abuse from un-friendly water users; • Wildlife that you may encounter in old boreholes (snakes; bees or wasps); • Exhaustion due to physical nature of the work. The work should therefore be done efficiently, effectively and with due care for the safety of the people involved. An abstraction survey may involve the following stakeholders: 1. WRA to provides legal mandate and technical know-how; 2. WRUA to represents local water users and provides local knowledge; 3. Public administration to provides safety; 4. Consultant to provides technical know-how, logistics, and additional capacity; 5. The water-using public. In order for the project collaboration to work effectively, all stakeholders should be involved in planning the proposed abstraction survey. 2.3.2 Scheduling of Abstraction Survey Groundwater abstraction surveys are typically required for aquifers where there is over- abstraction, which has led to tension over the availability of groundwater. It is therefore preferable to undertake the abstraction survey when water demand is greatest and abstraction 8 Guidelines for Groundwater Abstraction Surveys in Kenya activities are typical of the situation of maximum demand. This implies that the abstraction survey should be undertaken during the dry season. The abstraction survey is essentially a one- time snapshot of abstraction activities, which must be conducted during one continuous field campaign. 2.3.3 Public Notification Public notification is necessary for accountability, transparency and courtesy. In addition, in order to reduce hostility from water users whose land will be traversed during the survey, it is necessary to notify them. The timing of the notification can be considered from two points of view: • Notification immediately prior to the field work may affect the water use activity; • Notification substantially prior to the field work may be forgotten and so is less effective in reducing local hostility. Public notification can be conducted using any or all of the following methods: 1. Newspaper advertisement as a Public Notice, which can also be shown on public notice boards at the WRA Sub-regional office. An example is provided in Appendix 3; 2. Classified advertisement on a local vernacular radio station; 3. Meetings with WRUA members who can disseminate notification through WRUA communication channels; 4. Flyers to be disseminated through local schools and religious institutions; 5. Public meetings with public administration officials in the survey area. It is important that the local public administration is notified of the survey, as a water use survey can be a sensitive activity that may trigger local anger and possibly violence. This is best done by a formal letter from the WRA to the local public administration. 2.4 Fieldwork Preparations After development of a plan for ground water abstraction survey, it is important to carry out desk review to in order to gather all necessary information required for the study, prepare the field teams and ensure that equipment to be used are available and in proper working condition. 2.4.1 Desk Review A thorough desk review that is line with the objectives of the survey results in a proper fieldwork planning and hence credible results. Desk review is expected to provide the background information that guides the planning of fieldwork as it also provides a guide and indication of the minimum number of abstractors that are likely to be within the target area. This helps in logistics planning and establishing the number of people required to carry out the abstraction survey exercise within the available/allocated timelines. 9 Guidelines for Groundwater Abstraction Surveys in Kenya Some of the documents to be reviewed when preparing for fieldwork include: • Permit Database; • Any relevant Hydrogeological Assessment Reports; • Published geological and/or hydrogeological maps; • Published topographic maps, and any other relevant documents in the WRA’s possession. It is necessary to prepare a GIS map that includes the following components: • Underlying geology; • Topographic information and physical features (roads, settlements, dams, rivers etc. …); • Known (or suspected) BH locations; • Known (or suspected) shallow well locations; • Significant land uses that may influence groundwater abstraction (e.g. commercial farms; industry; etc. …); • Anything else relevant, such as a Groundwater Conservation or Protection Area; a National Park or Reserve, or a gazette Forest; a military base or other security protected area (such as State House). Additionally, with these data mapped, it is important to frame the boundaries of the groundwater abstraction survey area, get relevant data printed out – Borehole and shallow well locations, depths etc. (all relevant known characteristics, including Permit/abstraction data). These data will be carried by the field team(s) during the survey, and used to check on water users. As each user is surveyed, he/she is ticked off, or added to, the lists. 2.4.2 Reconnaissance Survey Reconnaissance surveys may be required depending on the scope of the exercise. The objective of the reconnaissance survey is to improve on fieldwork planning. If WRA is uncertain how to define the survey area, a reconnaissance survey would be necessary. If, however, they have a clear idea of an emerging hotspot, it should be relatively easy to frame the survey area the reconnaissance survey is not necessary. An illustrative example would be Kenol Town (Muranga County) or Makindu (Makueni County), where the boundaries would be pretty obvious. Circumstances on the ground will influence what the area should be though budgetary limitations are as likely to impose limits as well. In some cases, you may limit reconnaissance survey to areas of high population density, and exclude areas of known groundwater irrigation. In that instance, a reconnaissance survey could draw a transect line, from truly rural to town centre, and determine groundwater abstraction 500m either side of the transect line. This information is then used to inform the final boundaries of the survey area. In the case of a “Nanyuki Town” survey, for example, it would be difficult to ascribe different parts of the area to specific aquifers, because too little is known about them at this point. The rate of progress of data collection across the transect would also help determine how long the survey would take, and how many survey teams would be involved. 10 Guidelines for Groundwater Abstraction Surveys in Kenya A reconnaissance survey may also show where there are shortfalls or deficiencies in survey forms or field processes. 2.4.3 Composition of Field Teams The field team composition is partly dependent on the specific nature of the groundwater abstraction survey, but typically the team will comprise: 1. WRA staff, or someone authorised to enter land for the purposes of water resource management activities; 2. A WRUA member, to provide local legitimacy and acceptance of the survey; 3. WRA or consultant staff with technical understanding of the survey; 4. A local scout to provide local knowledge on routes and access across the survey area; 5. Vehicle and driver. 2.4.4 Training Field Teams Field team members must be trained in groundwater abstraction survey methods to ensure that the data is collected accurately, consistently, efficiently and safely. 2.4.5 Equipment Table 2-1 presents a list of typical equipment that is required for groundwater abstraction surveys: Table 2-1: Equipment List for Groundwater Abstraction Surveys NO. ABSTRACTION SURVEY EQUIPMENT COMMENTS 1 Stopwatch 2 Calculator 3 Bucket (25 litre) 4 Graduated measuring jug (2 litre) 5 Dipper If the survey includes water level measurements 6 GPS + Batteries Set the GPS datum as appropriate 7 Camera + Batteries/mobile phone 8 Whiteboard/Marker Pens/Pens/Pencils 9 Measuring Tape (100m, 30m & 3m) 10 Rope, weighted string 11 Data Capture Forms 12 Map 13 Field Notebook 14 Clipboard 15 Panga 16 First Aid Kit 17 Drinking Water 11 Guidelines for Groundwater Abstraction Surveys in Kenya NO. ABSTRACTION SURVEY EQUIPMENT COMMENTS 18 Torch + Batteries 19 VHF radio or mobile phone for communication 20 External Flow Meter See description in section 3.2 below. 2.4.6 Health and Safety Ensuring the health and safety of survey team members is paramount. Therefore, before you embark on fieldwork, assess the safety needs of the survey. This may include any or all of the following: • Physical safety (traffic, wildlife etc.); • Health (hydration, sunstroke etc.); • Working at heights (there may be cases where you have to climb a gantry to access a borehole headworks); • Electricity (be careful around generators and switchboards, these may not always have been wired properly). 2.5 Fieldwork Fieldwork activities should be guided as follows: • Form field teams as needed (informed by reconnaissance survey or desk review); • Divide the survey area into ‘survey zones’; • Each survey zone is allocated to a survey team or a survey phase, if only one team is available; • Commence abstraction survey with the order of survey for each ‘survey zone’ defined; • The field team accompanied by the appropriate local administration and WRUA officials, starts the survey with the first survey zone; • Unless the WRUA representative or local guide provides information to the contrary, the first known abstractor is visited and the field components of the survey are carried out; abstractor name, LR No, permits, actual or estimated abstraction and GW use, etc. The abstractor is asked about known nearby BHs, and sufficient information is collected from him/her to allow the survey team to find and visit these. As each pre-determined abstractor is accounted for, he/she is ticked off the field master list; • Where the WRUA representative or local guide knows of a Groundwater abstractor that the team has no information on, the team visits the site and carries out the field components of the survey and collects all relevant data; it should then provide guidance on the correct process the abstractor should go through in order to ‘regularise’ his/her abstraction. The ‘new’ abstractor is then asked about any other known nearby BHs and the survey process is repeated. • At intervals throughout the abstraction survey, data are conveyed to the WRA Office managing the survey. This includes not only all paper survey forms (or digital forms that may be used instead), but also all geo-referencing data. The managing office periodically 12 Guidelines for Groundwater Abstraction Surveys in Kenya plots these on a digital mapping platform (ARC-GIS, Google Earth, whatever is being used). This achieves two things: ▪ Survey progress is tracked and monitored; is the survey going to plan? If not, what needs to be done to bring it back on course (more survey teams, for example)? ▪ Un-surveyed areas become clear. These can either be easily explained (e.g. a National Park or Reserve, or a Forest Reserve; a large tract of ranch-land without significant groundwater development; an informal settlement; a zone of known hostile geology, such as an acid intrusion in otherwise un-metamorphosed Basement; a military base or other state protected area, or then targeted as areas of particular interest. The latter inevitably involves a door-to-door survey, knocking on doors and asking about known or suspected BHs or shallow wells and conducting field surveys as necessary; • All ‘hostile’ or ‘suspected’ boreholes or shallow well locations should be ‘captured’ and mapped; • Where there is obvious evidence that groundwater is being used (e.g. an obviously irrigated field or greenhouses in a farm the owner of which denies he/she has a borehole, that is nowhere near a surface water source), then a return visit with an Administration Policemen or the area Chief may be required; • The abstraction survey continues until all the ‘survey zones’ have been covered and all un- surveyed areas are explained. 2.6 Data and Record Management 2.6.1 Data Collection Forms and ODK The generic groundwater abstraction data collection form is shown in Appendix 1. The data collection form is designed to obtain comprehensive information on the water user, the nature and scale of water use, the nature of land use, and compliance with water regulations. The forms in the Guidelines should be coded into the Open Data Kit (web resource, ODK), for data capture during abstraction surveys. 2.6.2 Records Management Irrespective of whether data are collected manually (onto paper field forms) or with digital field data capture instruments (e.g. ProMark III GPS receivers), considerable thought must go into managing the data. During the Nairobi Borehole Census all field data were collected in a digital format using ProMark III receivers; at the end of the week field teams downloaded the .csv files from their ProMarks and sent them by email to the field team leader and the database manager. They were then incorporated into the Hydrocensus database. This was the most appropriate approach simply because of the volume of data collected (190 to 240 borehole questionnaire surveys per week). Smaller scale surveys may not need a digital database in Microsoft Access®, though manipulating and collating data in a digital environment (such as Microsoft Excel®) is almost always necessary. Take into account the scale of the survey when deciding how to manage the data collected. 13 Guidelines for Groundwater Abstraction Surveys in Kenya 2.7 Quality Control and Quality Assurance Quality Control (QC) is a set of activities for ensuring that errors are identified and corrected while Quality Assurance (QA) is a set of activities for ensuring there is credibility in the process and hence credibility in the results/data. Deliberate effort must be made to minimize errors especially in measurements. Errors due to procedure followed in data collection can be eliminated by following manufacturer’s instructions/user manual when using any particular equipment. In addition, it is good practice to take more than one measurement record. A significant variance in data may be an indication of error in procedure or entry of reading and this can be corrected immediately in the field. The collected data should the interrogated especially when the readings by the judgment of the officer in charge of data analysis seems to be “abnormal”. To support the process of quality control, it is always recommended that all field data remain available and are properly stored for reference whenever there is need. It is further advisable that when using mobile data capture equipment for data collection, the data should be sent to the server and downloaded as soon as possible so that any issues about the data can be addressed as soon as the possible when the details are still fresh in the field officer’s mind. 2.7.1 Flow Meter Quality Control and Quality Assurance Quality assurance in flow meters are activities for ensuring that the flow meter is in good working condition and that the readings are credible as per the manufacturers’ set conditions while Quality Control are activities in ensuring that the errors in the readings are corrected as per the manufacturer’s guidelines/instructions. Types of QA/QC for flow meters may include: • Routine maintenance; • Proper installation and mounting of flow meter probes; • Field diagnostics; • Routine factory calibration; • Routine in-house calibration. The appropriate user manual should be referred to for QA/QC requirements and suggestions for specific flow meters. 2.7.2 Flow Meter Manufacture Specifications Refer to the manufacturer specifications on the method, range accuracy, operating temperature and storage temperature for specific meters. 14 Guidelines for Groundwater Abstraction Surveys in Kenya 3. ABSTRACTION MEASUREMENT METHODS This chapter provides various methodologies that can be employed to determine the actual groundwater abstraction rate of individual water users. The approach adopted in the field will depend on the type of abstraction point, existence of online flow meters, and abstraction point access. The abstraction measurement method and measured or estimated abstraction rate should be recorded on the data capture form. 3.1 Internal/Online Flow Meter This is the easiest method to measure water abstraction in a pipeline and can be used when an internal or online flow meter exists. The general procedure is as follows: • Start stopwatch & record starting meter reading; • Stop stopwatch after approximately 5 minutes and record end meter reading; • Calculate the discharge rate. If the water user keeps regular abstraction records, or has submitted abstraction data to the WRA on a quarterly basis (as compliant permit holders should), these should be compared with field data. 3.2 External Flow Meter There are different types of flow meters that can be used to measure flow in pipes without opening the pipe where no internal/online flow meters exist. Detailed instructions for use of two selected external flow meters are provided in Appendix 4. The manufacturer’s instructions should be read and understood prior to any fieldwork. The general procedure is as follows: 1. Identify a suitable place to install the external flow meter. A good site should meet the following requirements: a. Is > 15 diameter lengths from pipe outlet b. Is > 20 diameter lengths from any fittings c. Pipe is flowing full d. Good contact can be made between the pipe and the flow meter sensors 2. Measure the pipe diameter (mm). 3. Estimate the pipe wall thickness (mm). 4. Install the meter as per the manufacturer’s instructions. This may include cleaning the location for installing the meter, setting the pipe clamps the required distance apart, installing the sensors at a defined separation, and greasing the sensors. 5. Take readings as per the manufacturer’s instructions. 15 Guidelines for Groundwater Abstraction Surveys in Kenya 3.3 Measured Volume over Recorded Time Formula: Q abstraction rate (L/s) = Vol (litres) / Time (sec) A. Bucket & Stopwatch • Select a point where the flow from the pipe can be channelled into a bucket (of known volume); • Measure the time to fill the bucket; • Measure the time to fill a graduated measuring jug for low discharge boreholes. B. Filling a Tank • Identify the first tank in system (i.e. before any offtakes); • Measure the internal diameter of the tank. If this is not possible, measure perimeter/circumference of the tank, and estimate wall thickness (note: use 250mm for a stone masonry tank). The internal diameter = perimeter (circumference) / (2π), less twice the wall thickness; • Close all outlets to tank; • Measure starting depth of water in tank (may require measuring stick inserted through roof opening); • Let water enter the tank to a reasonable depth; • Record filling time; • Measure end depth; • Calculate the volume of water in the tank (Vol = πr2  depth). 3.4 Calibrated Weirs A. V-Notch Weirs V-notch weirs are best placed in lined or unlined furrows or canals. The formula to convert water depth to discharge for a V-notch weir is: 𝑞 = 8 15 × 𝐶𝑑 × (2g) 1 2 × 𝑡𝑎𝑛( 𝜃 2 ) × ℎ 5 2 Where, q= flow rate Cd = discharge constant (Cd = 0.58 typically used for a 900 v-notch weir) θ = v-notch angle g = gravity (9.81 m/s²) h = head on the weir 16 Guidelines for Groundwater Abstraction Surveys in Kenya Table 3-1: Discharge Coefficients for a V-Notch Weir Head (metres) Weir Angle (degrees) 22.5 30 45 60 90 120 0.152 0.611 0.605 0.596 0.590 0.584 0.581 0.305 0.593 0.590 0.583 0.580 0.576 0.575 0.457 0.586 0.583 0.578 0.575 0.572 0.672 0.610 0.583 0.580 0.576 0.573 0.571 0.571 0.762 0.580 0.578 0.574 0.572 0.570 0.570 0.914 0.579 0.577 0.574 0.571 0.570 0.570 Discharge units: m3/s Tables of head and discharge for common v-notch weir configurations are available on the internet. 3.5 Estimating Water Abstraction If you do not have a meter and routine abstraction monitoring data, then you need to estimate abstraction using one of the following methods. 1. Estimate irrigated area and application rates; 2. Estimate based on pump capacity, pumping head and record of hours of pumping 3. Estimate based on electrical power bill 4. Estimate using livestock population or number of people being served 3.5.1 Estimate based on irrigated area The method described below is simplified for the purpose of estimating irrigation crop water applications. More detailed calculations could be used but it is recommended that more accurate ways of measurement (see section 3.1, 3.2, 3.3 and 3.4 above) could be used to obtain actual irrigation applications. The data needed are: • Area under irrigation (hectares); • Number of days in growing period; • Daily rainfall records (in mm) The area under irrigation can be estimated using one or more of the following methods: • Visual observations; • Report on land size from land owner or user; • GPS readings of corner points or using area function in GPS; • Measurement (using measuring tapes; suitable for relatively small areas only). Step 1: Estimate Total Crop Water Demand for Period 17 Guidelines for Groundwater Abstraction Surveys in Kenya For this simplified method, it has been assumed that irrigation application meets and exceeds crop evapotranspiration requirements which are assumed to be 6 mm per day; 1. Calculate monthly maximum crop water requirement = 30 Days x 6 mm per day = 180 mm/month; 2. Estimate crop water requirement met by rainfall: a. Equals zero for greenhouses; b. Equals 20% of average monthly rainfall for month with lowest average rainfall. The maximum crop water demand is calculated as follows: 𝐶𝑊𝐷 = 𝐶𝑊𝑅 − 𝑅 Where CWD = Maximum Monthly Crop Water Demand (mm/month); CWR = Maximum Crop Water Requirement (estimated at 180 mm/month); R = Rainfall (estimated at 20% of average monthly rainfall (mm/month) for month with least rainfall). Notes: The actual crop water demand is variable depending on crop type, growth stage and climate. Evaporation records can be used instead if these are available. More detailed methods of calculations can be obtained from FAO (1987) or from the 2005 Design Manual. Alternatively the District Irrigation Officer can assist in developing the crop water requirements specific to individual cases. Step 2: Calculate Total Abstraction for Irrigation Assume the following water supply conveyance efficiencies: • Piped systems – 1.2 • Lined Furrow/canal systems – 1.4 • Unlined Furrow/canal systems – 1.6. Assume the following water application/in-field efficiencies: • Drip systems – 1.2 • Overhead systems – 1.4 • Flood irrigation – 1.6. The daily abstraction requirement can be estimated as follows: Qvol = CWD/1000/30 x A x 10,000 x Supply Efficiency x Application Efficiency Where Qvol = daily abstraction volume (m3/day) 18 Guidelines for Groundwater Abstraction Surveys in Kenya CWD = Crop Water Demand (mm/month) A = area under irrigation (hectares). 3.5.2 Estimate based on pump curves Data needed are: • Pump Rating Curve (provided by pump manufacturer); • Pumping Head (m); • Records of pumping hours (hours). It is assumed that the pump is operating at 60% efficiency. Step 1: Determine pump discharge Examine the pump rating curve and establish the discharge for the pumping head. The following information is required: • Pumping head. This is estimated from field observations and measurements; • Pump curve (obtain from internet). Step 2: Determine total volume pumped Total Volume pumped (m3) = Pump Discharge Rate (m3/hr) x Total Pumping Time (hr) x 0.6. 3.5.3 Estimate based on electrical power bill Data needed are: • Total power consumed (Kw-hr); • Pump power rating (Kw – can be converted from horsepower); • Pump Rating Curve (provided by pump manufacturer); • Pumping Head (m). It is assumed that the pump is operating at 60% efficiency. 3.5.4 Estimate Using Population Served During the survey process, when water users are being interviewed, try to determine from them how many people/families/livestock and type of livestock rely on the resource for water supply. Also try to determine what water is used for. Either ask water users how many jerry cans they use per unit per day (physical count), or assume 25 litres per human per day (Basic Human Need); use consumption rates for livestock as listed in the 2005 Design Manual for Water Supply. These would typically be over-estimates, as the UNHCR determined – their minimum supply level is set at 15 litres per person per day, and is based on field data from camps all over the world. This may be considered a practical minimum for ASAL areas and areas where water resources are scarce. 19 Guidelines for Groundwater Abstraction Surveys in Kenya 4. DATA ANALYSIS AND REPORTING 4.1 Objectives Expressed simply, data analysis and reporting converts field data into information that can be used to inform the water allocation process. It should provide a snap shot of current conditions, show where demand for groundwater is highest and indicate areas where a groundwater resource may be under pressure. Data may be mapped, presented as tables or charts or otherwise described in report text. 4.2 Data Analysis – Groundwater Abstraction The objective of a groundwater abstraction survey is to: • Determine how much groundwater is abstracted and what it is used for; • Determine the spatial distribution of groundwater abstraction; • From these data, locate potential “hotspots”; • Use these patterns and trends to inform water allocation. 4.3 Data Analysis – Permit Compliance The abstraction survey is incomplete without comparing the field abstraction data with the WRA permits. This exercise checks authorisation/permit data and determining whether records match field observations. Appendix 2 presents the form that can be used to extract authorisation/permit data which is matched with abstraction or effluent discharge points that were identified in the field. 4.4 Mapping All field data should be mapped at an appropriate scale; this presents data spatially and allows a useful overview of abstraction. Maps may also highlight areas in which no groundwater abstraction appears to take place, and may call for follow-up field visits. Maps will highlight ‘hotspot’ areas, which may then feed into a water allocation plan. 4.5 Reporting and Stakeholder Presentation A report describing the abstraction survey and presenting the survey results should be written. 4.5.1 Discussion Points The report should highlight the major findings of the survey, such as: • Abstraction ‘hotspots’: - o Urban areas – domestic/commercial/public water demand o Rural areas – irrigation water demand. • Areas where there is little groundwater abstraction: - 20 Guidelines for Groundwater Abstraction Surveys in Kenya o Hostile geology (poor groundwater conditions) o More easily accessible alternatives (surface water) o Limited water demand. • Aquifer characteristics may be highlighted: - o Zones of high hydraulic conductivity/transmissivity. 4.5.2 Deliverables Check that the findings of the survey and the report describing it meet the stated objectives of the survey (as described above in Section 2.1). 21 Guidelines for Groundwater Abstraction Surveys in Kenya APPENDIX 1 GW ABSTRACTION SURVEY FORM Interviewer briefly explains abstraction survey, asks to see BH paperwork. 1 Date 2 Time 3 Team/area/interviewer 4 Questionnaire reference number 5 X coord 6 Y coord 7 Z coord Zone 8 Location marked BH Gate Other 9 Gate number (if applicable) 10 Road / Street / Locality 11 Sub-location 12 Location 13 Sub-county 14 County 15 Interviewee's name Interviewee's Tel. No. 16 Relationship to BH owner BH owner Family member Employee Other (specify) 17 LR No 18 BH owner name 19 P O Box Post Office 20 Post Office Code 21 Contact tel. no 22 Email address 23 Borehole Number 24 Permit Number 25 Old Permit Number 26 Authorised use(s) and volumes Public m3d Domestic m3d Livestock m3d Sub Irrig m3d 22 Guidelines for Groundwater Abstraction Surveys in Kenya Com Irrig m3d Industrial/Commercial m3d Other (specify) m3d 27 Total volume approved m3d 28 Expiry date 29 Actual water use yes/no Qty UNIT Rate Vol Public people m3d Domestic people m3d Livestock LSU m3d Sub Irrig ha m3d Com Irrig ha m3d Industrial/Commercial m3d Other m3d 30 Volume Used m3d 31 Alternative water source? Piped supply Rainwater Other (specify) 32 Flowmeter in place Yes/No 33 Flowmeter name Kent Arad Sensus Pompes Delpechin ABB Other 34 Flowmeter number 35 Flowmeter reading 36 Does the water user pay No Water Charges? Monthly Quarterly Biannually Don't know 37 Is a dipper tube in place? Yes/No 38 Is the BH monitored by anyone? Yes/No 39 Have you noticed any changes in Falling yield BH behaviour? Declining quality Increasing pwr cost Collapse Rusting rising main 23 Guidelines for Groundwater Abstraction Surveys in Kenya Other 40 Have you made any changes Yes Deepened it to the BH? Repl.w. deeper borehole Increased its diameter Re-cased it Changed the pump Other No 41 Any comments? 42 Capture/No Capture Success Unknown Failure Left documents, contacts Agreed to return date 43 Match/No Match Match made Against LR No Against Owner name Against C- number Against Permit number No match made No borehole Borehole suspected Interviewer thanks BH owner, leaves details of the WRA tel no 24 Guidelines for Groundwater Abstraction Surveys in Kenya APPENDIX 2 GW PERMIT COMPLIANCE CHECKLIST ABSTRACTION/EFFLUENT DISCHARGE COMPLIANCE CHECKLIST ABSTRACTION  EFFLUENT DISCHARGE  Name of WRUA Date Name of Data Collector Contact Number Details of Physical Location Name of Aquifer WPT No. (from GPS) Grid Reference of point of abstraction/effluent discharge (taken by GPS with appropriate datum and units) Latitude (Northing) Longitude (Easting) Details of Land L/R Number Sub-location Location Division District Details of Abstractor/Effluent discharger Name of Informant Name of Abstractor/Effluent Discharger Relationship of water user to land owner (tick one) Land owner  Family member  Leases land  Don’t know  Category of Abstractor/Effluent Discharger (tick one) Individual  Group (CBO, Society)  Company  Institution  Contact details of Abstractor/Effluent Discharger Postal Address Telephone Email Water Use Activity (tick one or more) Groundwater Shallow well  Borehole  Purpose of Water Use Activity (tick one or more) Domestic  Livestock  Public  Subsistence Irrigation  Commercial Irrigation  Industry/Commercial  Effluent disposal  Other (specify)  Permit Compliance Name on Permit/Authorisation L/R No. on Permit/Authorisation 25 Guidelines for Groundwater Abstraction Surveys in Kenya Grid Ref on Permit/Authorisation Long/E Lat/N Status of Permit Applied for  Date: Authorisation issued  Date issued: Number: Permit issued  Date issued: Number: Expiry date: If no valid permit, what is the reason? Category of user (Aquifer specific – insert applicable values from Permit Thresholds document) A  B  C  D  Don’t know  < m3/d > XX - < XX m3/d > XX - < XX m3/d > XX m3/d Comment Compliance with conditions of permit/authorisation Condition Required (tick if yes) Condition Implemented (tick if yes) Water meter/measuring device   Payment of water use charges   Prepare & submit EDCP   Prepare & submit SWCP   WQ Sampling   Join WRUA   Other conditions (if any; describe)   Volume abstracted/effluent discharged (m3/day) Authorised Actual abstraction/discharge Comment Water Use Data Is abstraction/effluent discharge measured on a regular basis? Yes  No  Perceptions of Abstractor/Effluent Discharger Are you a member of the WRUA? Yes  No  Has your abstraction point been inspected by WRA staff? Yes  No  Is your water use activity vulnerable to water use activities up- aquifer? Yes  No  Can your water use activity negatively affect water users down- aquifer? Yes  No  How should the WRA communicate with water users? (tick one or more) WRUA  Radio  Newspaper  Posting at Chief’s office  Other (specify)  Other comments (as necessary) Signature of Data Collector Name of WRUA Official 26 Guidelines for Groundwater Abstraction Surveys in Kenya Signature of WRUA officials 27 Guidelines for Groundwater Abstraction Surveys in Kenya APPENDIX 3 SAMPLE NEWSPAPER ADVERTISEMENT GAZETTE NOTIFICATION OF GROUNDWATER ABSTRACTION SURVEY The underlined statements are to be filled in respective of the location and date of the abstraction survey. PUBLIC NOTICE NOTICE OF THE CONDUCT OF ABSTRACTION SURVEY IN AQUIFER The Water Resources Authority is the lead agency in water resources management in the country. The Authority is mandated under the Water Act 2016 to regulate the management and use of water resources. Pursuant to the requirements of the Water Act 2016, Water Resources Management Rules 2007 and the National Water Master Plan, the Water Resources Authority intends to carry out a Groundwater Abstraction Survey in the XX Aquifer. The survey is intended to provide information on the availability, apportionment and utilization of water resources within XX Aquifer. This activity with support the preparation of a Water Allocation Plan for the XX Aquifer to improve water allocation and control of water use activities. In carrying out the survey, activities will include but are not limited to: 1. Fieldwork and site visits to identify groundwater abstractors; 2. Measurements of discharge from boreholes, shallow wells and springs; 3. Assessing total groundwater use by measurement and observation of any civil or field works; 4. Consultations with groundwater users in regard to groundwater abstractions; 5. Geo-referencing and photographing of the works or relevant aspects of the abstraction system. The exercise will be conducted by WRA, the local Water Resource Users Associations and a Consultant. The exercise is scheduled to commence on the date. Water users and other stakeholders from the XX Aquifer are requested to support this exercise by availing themselves to the team, permitting access to site and providing the necessary information. For further information and/or any enquiries, contact WRA or the respective WRUA. 28 Guidelines for Groundwater Abstraction Surveys in Kenya APPENDIX 4 INSTRUCTIONS FOR USE FOR SELECTED FLOW METERS A. Micronics PF220 Figure 4-1 Micronics PF220 Flow Meter i. Test units Discharge m3/s or l/min ii. Instructions for use 6. Identify suitable place to install external flow meter. A good site must be: a. > 15 diameter lengths from pipe outlet b. > 20 diameter lengths from any fittings; c. The pipe is flowing full; d. Good contact can be made between sensors and pipe. 7. Measure diameter of pipe (mm); 8. Estimate pipe wall thickness (mm); 9. Clean location for installing meter; 10. Turn meter on & enter basic data; 11. Install pipe clamps and set distance apart; 12. Lightly grease the sensors; 13. Install the sensors and set the proper distance separation; 14. Hook up cables; 15. Take readings; repeat until satisfied that values are stable and internally consistent. iii. Calibration Notes See User Manual. Pipe clamps Sensors Cables & chains for securing clamps Grease Meter 29 Guidelines for Groundwater Abstraction Surveys in Kenya B. Shenitch Stuff 300 Figure 4-2: Shenitch Stuff 300 Flow Meter i. Test units Discharge m3/s or l/min ii. Instructions for use 1. Identify suitable place to install external flow meter. A good site must be: a. > 15 diameter lengths from pipe outlet b. > 20 diameter lengths from any fittings; c. The pipe is flowing full; d. Good contact can be made between sensors and pipe. 2. Measure diameter of pipe (mm); 3. Estimate pipe wall thickness (mm); 4. Clean the pipe surface in the location chosen for installing the meter; 5. Turn the meter on & enter basic data; 6. Install the pipe clamps; 7. Lightly grease the sensors; 8. Install the sensors and set the pipe clamps at the proper separation distance; 9. Hook up the cables; 10. Take readings; repeat until you are satisfied that values are stable and internally consistent. iii. Calibration Notes See User Manual. Pipe clamps & sensors 30 Guidelines for Groundwater Abstraction Surveys in Kenya APPENDIX 5 GROUNDWATER SURVEYS – SOME THEORETICAL EXAMPLES In the sections that follow, a range of examples of possible groundwater surveys (both abstraction and water quality) are described, in order to highlight elements of such surveys. All discuss real Kenyan environments; all are possible survey targets. The following are considered: 1. An extensive rural area with shallow groundwater (a part of eastern Kwale County); 2. An extensive rural area with deep groundwater (northern Laikipia); 3. An arid town with shallow groundwater (El Wak or Wajir); 4. An arid town with shallow and deep groundwater (Lodwar); 5. A semi-arid town with deep groundwater (Makindu) 6. A medium-sized town with deep groundwater (Nanyuki); 7. A conurbation with shallow groundwater (Mombasa). These have been outlined at various levels of detail, partly reflecting a lack of relevant data. ABBREVIATIONS CETRAD Centre for Training and Integrated Research in ASAL Development CWSB Coast Water Service Board GoK Government of Kenya KISCOL Kwale International Sugar Company Ltd KWAWASCO Kwale Water and Sewerage Company LOWASCO Lodwar Water and Sewerage Company MOWASSCO Mombasa Water and Sewerage Company NAWASCO Nanyuki Water and Sewerage Company NDMA National Drought Management Authority PDB Permit database SRO Sub-regional office WAJWASCO Wajir Water and Sewerage Company WRA Water Resources Authority WRAP Water Resources Assessment Project WRM Rules Water Resources Management Rules, 2007 WRUA Water Resources Users Association 31 Guidelines for Groundwater Abstraction Surveys in Kenya A1. A RURAL AREA UNDERLAIN BY SHALLOW GROUNDWATER RESOURCES (PARTS OF MATUGA AND MSAMBWENI SUB-COUNTIES) A1.1 Survey objectives Objectives of a groundwater abstraction survey; to determine the amount of water that is abstracted from groundwater resources in the survey area. Objectives of a groundwater quality survey; to determine the extent of saltwater intrusion in the survey area. Other opportunities; to determine the level of compliance with the WRM Rules (2007)1, and to capture hitherto un-captured groundwater users and improve water charge revenue. A1.2 Survey area The survey area is defined as the rural zone lying between the Ramisi River in the south and the southern edge of Ukunda Town in the north; the northern boundary is a west to east line along the north edge of the Muhaka Forest. The eastern and western boundaries are the shoreline (east) and the low lying range of hills (west); the western boundary is, somewhat arbitrarily, defined as the 65mamsl contour line. It includes Msambweni Town. A1.3 Hydrogeological context The survey area is underlain by Pleistocene coral limestones along the shore and Pleistocene sands and lagoonal deposits inland; both form a locally-important unconfined aquifer. Along the western edge Pliocene Magarini Formation sands occur, and form a poor aquifer. At depth beneath parts of the area, fractured and faulted Mto Mkuu, Kambe and Mazeras Formation sediments of Jurassic age host an efficient confined aquifer that is exploited by commercial agricultural and mining operations. A1.4 Planning the surveys The survey planning phase would involve a broad range of stakeholders, including but not necessarily limited to, the following: • WRA SRO Mombasa; • Mkurumudzi WRUA; • Kwale County Government/ Kenya Water Security and Climate Resilience Project – Phase 2; • Kwale Water and Sewerage Company (KWAWASCO); • South Coast Residents Association; • Kenya Association of Hoteliers and Catering; • Kwale International Sugar Company Ltd (KISCOL); • Base Titanium Ltd (Base); • World Wildlife Fund (WWF); • National Drought Management Authority (NDMA); • Others … 1 Government of Kenya (GoK) (2007): The Water Resources Management Rules, 2007. Legal Notice No. 171 of 2007. Nairobi, Kenya. 32 Guidelines for Groundwater Abstraction Surveys in Kenya The surveys would be carried out during the long dry season (January to March), when water resources are at their most stressed. The surveys will require multiple survey teams if the task is to be completed within a reasonable period of time. A1.5 Conducting the surveys It is already known that there are a large number of shallow boreholes and wells in the area, many equipped with handpumps. In addition, there are a number of high capacity boreholes constructed by KISCOL and Base. KWAWASCO has at least three public water supply borehole/wells, and addition public W/S boreholes are planned. Therefore, this will be a detailed survey that aims to visit and capture all groundwater sources; these will include unprotected and protected shallow wells and springs; and shallow and deep boreholes. It is conservatively estimated that at least 500 groundwater sources exist in the area, the vast majority of which are small-scale rural water points. It is also already known that seawater intrusion and groundwater pollution has already occurred in the survey area2 and has almost certainly continued, given both population and business growth in the area. All georeference data will be collected using hand-held GPS receivers; elevation must be captured. A1.6 Groundwater abstraction survey Equipment and methods for the manual measurement of groundwater abstraction will be required, as well as electro-magnetic flow metres. In recent years, rural electrification has seen a significant number of boreholes/wells formerly equipped with handpumps retrofitted with single-phase electric pumps; relatively few of these are fitted with flow meters. Large-scale groundwater users generally comply with the WRM Rules (2007) and submit abstraction data and water use charges to the WRA. This covers KISCOL, Base and possibly some of the larger hotels in the Msambweni area. The majority of groundwater users are small-scale (<10m3/d), and do not pay water use charges. A1.7 Groundwater quality survey Equipment for field chemistry (electrical conductivity, temperature and pH at a minimum) will be essential. At its most simple, a groundwater quality survey could be limited to the above field parameters; however, a more rigorous survey would include major anions and cations as well as specific seawater intrusion indicators (bromide, or strontium and boron). Not all sites would be subject to rigorous water chemistry analysis, on the grounds of costs; water samples from a quarter of all sites will be collected and analysed. The groundwater quality survey may include bacteriological parameters (total coliforms and E. coli). This would significantly increase the cost and logistical complexity of the survey. 2 Tole MP (1997): Pollution of groundwater in the coastal Kwale District, Kenya. In: Sustainability of Water Resources Under Increasing Uncertainty (Proc. Rabat Symposium S1, April 1997), pp. 287-97, IAHS Publ. no. 240, 1997. 33 Guidelines for Groundwater Abstraction Surveys in Kenya A2. A RANCHING AREA UNDERLAIN BY DEEP GROUNDWATER RESOURCES (NORTHERN PART OF LAIKIPIA COUNTY) A2.1 Survey objectives Objectives of a groundwater abstraction survey; to determine the amount of water that is abstracted from groundwater resources in the survey area. Objectives of a groundwater quality survey; to determine the significance and range of dissolved fluoride in the deep aquifer. Other opportunities; to determine the level of compliance with the WRM Rules (2007), and to capture hitherto un-captured groundwater users and improve water charge revenue. A2.2 Survey area The survey area is large, but the number of groundwater users is relatively small, due to the extensive land holdings in the area. The surveys are to cover the entire northern part of Laikipia County as far south as an east to west line through Rumuruti Town. A2.3 Hydrogeological context Generally, the survey area is underlain by Miocene and younger volcanics to the south and metamorphic Basement to the north and north east. In the south eastern part, Nanyuki Formation glacial deposits have been reported. A2.4 Planning the surveys There are numerous stakeholders that would be involved in the survey planning phase, including but not necessarily limited to, the following: • WRA Ewaso Ngiro North; • Relevant WRUAs; • Laikipia County Government; • Mount Kenya Ewaso Water Partnership; • Laikipia Wildlife Forum and other conservation groups (too numerous to mention here); • Mpala Research Centre; • CETRAD; • Kenya Wildlife Service; • National Drought Management Authority (NDMA); • Others … A2.5 Conducting the surveys These surveys will benefit from significant advance planning, since most (if not nearly all) existing boreholes and springs should be captured by the PDB, hydrogeological survey reports and historic data already in the WRA’s possession. A field map, with the following details provided, should be drawn up when planning the surveys: 34 Guidelines for Groundwater Abstraction Surveys in Kenya • Underlying geology; • Topographic information and physical features (roads, settlements, dams, rivers etc. …); • Known (or suspected) BH locations; • Known (or suspected) shallow well locations (few, if any); • Known spring locations; see WRAP report3; • Significant land uses that may influence groundwater abstraction (e.g. commercial farms); ranch boundaries should be mapped, to the extent possible; • Anything else relevant, such as a Groundwater Conservation or Protection Area; a National Park or Reserve, or a gazetted Forest. In conjunction with water users and the major stakeholders, perform a verification exercise, initially by email and face to face meetings, and ultimately during fieldwork. A2.6 Groundwater abstraction survey Standard equipment for groundwater abstraction surveys, both manual and electro-magnetic meter methods. Flow meters should be checked. A2.7 Groundwater quality survey In addition to field parameters, collect dedicated samples for laboratory analysis of dissolved fluoride. 3 Water Resources Assessment Project (1987): Water Resources Assessment Study in Laikipia District. Ministry of Water Development, Nairobi. 35 Guidelines for Groundwater Abstraction Surveys in Kenya A3. AN ARID TOWN WITH SHALLOW GROUNDWATER (EL WAK; WAJIR) A3.1 Survey objectives Objectives of a groundwater abstraction survey; to determine the amount of water that is abstracted from shallow groundwater resources in the survey area. Objectives of a groundwater quality survey; to determine the significance and range of dissolved nitrate and nitrite in the shallow aquifer in Wajir; and sulphate in the shallow aquifer in El Wak. Other opportunities; to determine the level of compliance with the WRM Rules (2007), and to capture hitherto un-captured groundwater users and improve water charge revenue. NOTE: this survey specifically excludes deep groundwater resources, which are known to exist in the El Wak area (but not the Wajir area, except for the Mansa Guda Formation, encountered at depth north of Wajir). A3.2 Survey area In both cases, the survey area would encompass the entire built-up parts of these towns, as well as the peripheral shallow wellfields that surround these towns. At Wajir, this would include the military base east of the town. At El Wak, it would exclude that part of the town that lies within Somalia. A3.3 Hydrogeological context Beneath Wajir the geology comprises surface deposits of arenaceous limestone, calcareous sandstone, marl, and gypsum. Limestone and gypsum of Pleistocene age occur beneath the surface in a circular area around El Wak. These beds (the Wajir and El Wak Beds respectively), were deposited in arid to semi-arid environments by ephemeral streams or in playas and lakes; they reflect climatic variations during the Pleistocene, including wetter periods than the present. Shallow groundwater is encountered beneath both towns, within 20m of ground surface in Wajir and with 25m of the surface in El Wak (based on Swarzenski et al, 1977)4. Both of these shallow groundwaters are known to be naturally contaminated; in Wajir, a palaeosol that is naturally rich in soluble nitrate exists, and leaches into the shallow aquifer during recharge events. In El Wak, waters contain naturally elevated sulphate, due to the presence of soluble gypsum in the sub-surface; as with Wajir, direct recharge from rain leaches out the soluble calcium and sulphate (Swarzenski et al, 1997). A3.4 Planning the surveys A detailed assessment of the stakeholders who would be relevant in planning these surveys is not given here; however, they would include but definitely not be limited to, the following: • WRA Ewaso Ngiro North; • Relevant WRUAs and Pastoralist Associations; 4 Swarzenski WV & Mundorff MJ (1977): Geohydrology of North Eastern Province, Kenya. USGS Water Supply Paper 1757-N. 36 Guidelines for Groundwater Abstraction Surveys in Kenya • Wajir County Government (Wajir): Mandera County Government (El Wak); • Wajir Water and Sewerage Company (WAJWASCO); • El Wak water supply (County-managed?); • National Drought Management Authority (NDMA); • Oxfam, Mercy Corps and other relevant NGOs; • Others … A3.5 Conducting the surveys There are numerous shallow wells in each of these towns (over 300 in Wajir alone in the mid-1970s; Swarzenski et al, 1977); few are likely to have been captured in the PDB, other than public water supply wells. Consequently, these surveys would be designed on the assumption of house to house visits in urbanised areas, which is manpower-intensive and time consuming. Peripheral wellfields serving livestock water needs are considerably easier to survey; these wells are prominent structures that are easily visible. A3.6 Groundwater abstraction survey Standard equipment for groundwater abstraction surveys, both manual and electro-magnetic meter methods. Flow meters – if present – should be checked. A3.7 Groundwater quality survey In addition to field parameters, collect dedicated samples for laboratory analysis of dissolved nitrate (Wajir) and sulphate (El Wak). 37 Guidelines for Groundwater Abstraction Surveys in Kenya A4. AN ARID TOWN WITH SHALLOW AND DEEP GROUNDWATER (LODWAR) A4.1 Survey objectives Objectives of a groundwater abstraction survey; to determine the amount of water that is abstracted from groundwater resources in the survey area. Objectives of a groundwater quality survey; to determine the significance and range of salinisation in the deep aquifer. Other opportunities; to determine the level of compliance with the WRM Rules (2007), and to capture hitherto un-captured groundwater users and improve water charge revenue. A4.2 Survey area The survey area is tentatively defined as Lodwar Town, Nakwamekwi, and Napetet. Kanamkemer (south of the Turkwel River), should be included, as it is a fast-growing peri-urban area (it lies in a separate location, comprising Kanamkemer and Nawaitorong sub-locations. A4.3 Hydrogeological context The hydrogeological context is either alluvial (along the course of the Turkwel and Kawalase Rivers), or Miocene phonolites and nephelinites intercalated with sediments and/or volcanoclasts. For the purposes of this study, the ‘Lodwar Basin’ aquifer is excluded5. A4.4 Planning the surveys A detailed assessment of the stakeholders who would be relevant in planning these surveys is not given here; however, they would include but definitely not be limited to, the following: • WRA Lodwar SRO; • Relevant WRUAs; • Turkana County Government; • Lodwar Water and Sewerage Company (LOWASCO); • Diocese of Lodwar; • Other actors in water supply provision or support (UNICEF; UN WOMEN; Oxfam; Practical Action; Friends of Lake Turkana and World Vision, among others); • National Drought Management Authority (NDMA); • Others … A4.5 Conducting the surveys 5 Radar Technologies International (2013): Advanced Survey of Groundwater Resources of Northern and Central Turkana, Kenya. Final Technical Report. 38 Guidelines for Groundwater Abstraction Surveys in Kenya There are numerous shallow and deep boreholes in and around Lodwar, ranging in depth from 18 to >100m. LOWASCO operates approximately 10 functional production boreholes for public water supply, located along the Turkwel River6. A number of boreholes are equipped with handpumps. Some boreholes are likely to have been captured by the PDB and other documents7, so a draft fieldwork map should be generated as part of the pre-survey planning process. These surveys would be carried out as laid down in the Guidelines. A4.6 Groundwater abstraction survey Standard equipment for groundwater abstraction surveys, both manual and electro-magnetic meter methods. Flow meters – if present – should be checked. A4.7 Groundwater quality survey In addition to field parameters, collect dedicated samples for laboratory analysis of major anions and cations from all sites. 6 Haines S, Imana CA, Opondo M, Ouma G & Rayner S (2017): Weather and climate knowledge for water security: Institutional roles and relationships in Turkana. REACH Working Paper 5, University of Oxford, Oxford, UK. 7 Wendo VAJ (2015): Design of an Aquifer Recharge System in Lodwar, Turkana. BSc Engineering Design Project, University of Nairobi, May 2015. 39 Guidelines for Groundwater Abstraction Surveys in Kenya A5. A SEMI-ARID TOWN WITH DEEP GROUNDWATER (MAKINDU) A5.1 Survey objectives Objectives of a groundwater abstraction survey; to determine the amount of water that is abstracted from groundwater resources in the survey area. This excludes attraction from the springs located west of the Town, which occur in a different geological context. Objectives of a groundwater quality survey; to determine the significance and range of dissolved solids in the deep aquifer. Other opportunities; to determine the level of compliance with the WRM Rules (2007), and to capture hitherto un-captured groundwater users and improve water charge revenue. A5.2 Survey area The survey area is limited to the urbanised area of Makindu Town located east of the Chyulu Hills volcanics. A5.3 Hydrogeological context Makindu is underlain by undifferentiated metamorphic Basement, principally comprising granitoid and biotite gneisses. For reasons that are probably associated with either recent geological metamorphosis, or preferential lateral allogenic recharge from the west, yields in Makindu area boreholes are often higher than is typically expected of Basement. A5.4 Planning the surveys A detailed assessment of the stakeholders who would be relevant in planning these surveys is not given here; however, they would include but definitely not be limited to, the following: • WRA Kibwezi SRO; • Relevant WRUA; • Makueni County Government; • National Drought Management Authority (NDMA); • Others … A5.5 Conducting the surveys Some boreholes are likely to have been captured by the PDB and other documents, so a draft fieldwork map should be generated as part of the pre-survey planning process. These surveys would be carried out as laid down in the Guidelines. A5.6 Groundwater abstraction survey Standard equipment for groundwater abstraction surveys, both manual and electro-magnetic meter methods. Flow meters – if present – should be checked. A5.7 Groundwater quality survey 40 Guidelines for Groundwater Abstraction Surveys in Kenya In addition to field parameters, collect dedicated samples for laboratory analysis of major anions and cations from all sites. A6. A MEDIUM-SIZED TOWN WITH DEEP GROUNDWATER (NANYUKI) A6.1 Survey objectives Objectives of a groundwater abstraction survey; to determine the amount of water that is abstracted from groundwater resources in the survey area. Objectives of a groundwater quality survey; to determine the significance and range of dissolved fluoride in the deep aquifer. Other opportunities; to determine the level of compliance with the WRM Rules (2007), and to capture hitherto un-captured groundwater users and improve water charge revenue. A6.2 Survey area The area to be covered by a groundwater abstraction and water quality survey of Nanyuki is difficult to determine in an abstract or theoretical setting. Nanyuki is a large and growing town, with a 2009 population of 32,189 (which only covers an area of 78km2). However, the water services provider, Nanyuki Water and Sewerage Company (NAWASCO), has a service area population of 95,283 and produces an average of 10,926m3/d of water from surface water sources and a few boreholes8. A6.3 Hydrogeological context Nanyuki Town is underlain by lavas, volcanoclastic and glacial deposits arising from Mount Kenya. These give rise to a broad range of hydrogeological conditions, leading to borehole test yields of up to 70m3/hr of groundwater of variable quality. Groundwaters often contain excessive dissolved fluoride. A6.4 Planning the surveys A thorough study would be required to define the survey area. This could be based on a preliminary field map showing known borehole and spring locations, and the survey area selected on the grounds of apparent borehole density; or by means of a reconnaissance survey along a transect through the town. There are known to be a significant number of boreholes in and around the Town. A detailed assessment of the stakeholders who would be relevant in planning these surveys is not given here; however, they would include but definitely not be limited to, the following: • WRA Nanyuki SRO; • Relevant WRUAs; • Laikipia County Government; • Nanyuki Water and Sewerage Company (NAWASCO); • CETRAD; • Rural Focus Ltd; • National Drought Management Authority (NDMA); 8 Water Services Regulatory Board (WASREB) (2018): Impact Issue No. 10. 41 Guidelines for Groundwater Abstraction Surveys in Kenya • Others … A6.5 Conducting the surveys These surveys would be carried out as laid down in the Guidelines; there is likely to be a substantial door-to-door component. A6.6 Groundwater abstraction survey Standard equipment for groundwater abstraction surveys, both manual and electro-magnetic meter methods. Flow meters – if present – should be checked. A6.7 Groundwater quality survey In addition to field parameters, collect dedicated samples for laboratory analysis of dissolved fluoride. 42 Guidelines for Groundwater Abstraction Surveys in Kenya A7. A CONURBATION WITH SHALLOW GROUNDWATER (MOMBASA) A7.1 Survey objectives Objectives of a groundwater abstraction survey; to determine the amount of water that is abstracted from groundwater resources in the survey area. Objectives of a groundwater quality survey; to determine the significance of saltwater intrusion into the shallow aquifer. Other opportunities; to determine the level of compliance with the WRM Rules (2007), and to capture hitherto un-captured groundwater users and improve water charge revenue. A7.2 Survey area Determining the area for an abstraction and water quality survey of Mombasa has the same problems, uncertainties and pitfalls as determining the Nanyuki survey area. The importance of groundwater use on Mombasa Island and both the southern and northern Mombasa Coasts is widely acknowledged to be significant, but the extent and scope of abstraction is largely unknown. The presence of illegal (or unauthorised) boreholes is widely suspected, particularly on the Island. Numerous shallow wells are prevalent in Kisauni and Likoni (South Coast). Furthermore, previous studies have demonstrated that the shallow aquifers underlying Kisauni (North Coast) and the Island are both contaminated by pollution9. Aquifers beneath Kisauni have more recently been found to contain water with electrical conductivity values exceed 1,500µS/cm, inferring seawater intrusion10. In this example, the Kisauni/Bamburi area is assumed to be the target survey area, extending from areas occupied by informal settlement eastwards towards the sea. A7.3 Hydrogeological context The Kisauni area is underlain by the following formations, in order of increasing age and increasing distance from the coast: • Pleistocene fossil coral reefs and coral breccia; • Pleistocene lagoonal sands and corals (Kilindini Formation); • Pleistocene windblown and superficial sands; • Upper Jurassic shales (Mto Mkuu Formation); • Middle Jurassic limestone (Kambe Limestone). All these formations – even the shales – host a shallow aquifer. The Pleistocene material has the greatest groundwater potential, particularly the fossils corals and lagoonal deposits. 9 Munga D, Kitheka JU, Mwaguni SM, Barongo J, Massa HS, Mwangi S, Ong’anda H, Mdoe F, & Opello G (2005): Vulnerability and Pollution of Groundwater in the Kisauni Area, Mombasa, Kenya. Project on Assessment of Pollution Status and Vulnerability of Water Supply Aquifers in African Cities, UNEP/UNESCO/UN-HABITAT/ECA, April 2005. 10 Idowu TE, Nyadawa M & K’Orowe MO (2017): Hydrogeochemical assessment of a coastal aquifer using statistical and geospatial techniques: case study of Mombasa North Coast, Kenya. Environ Earth Sci (2017) Vol. 76, 422 (18 pp.). 43 Guidelines for Groundwater Abstraction Surveys in Kenya A7.4 Planning the surveys A detailed assessment of the stakeholders who would be relevant in planning these surveys is not given here; however, they would include but definitely not be limited to, the following: • WRA Mombasa SRO; • Relevant WRUAs; • Mombasa County Government; • Mombasa Water and Sewerage Company (MOWASSCO); • Coast Water Service Board (CWSB); • Kenya Association of Hotelkeepers and Caterers; • Others … A thorough study would be required to define ‘survey zones’ for each survey team or survey phase; a reconnaissance survey along a transect through the survey area might assist in defining zones on the basis of different land uses. There are known to be a significant number of shallow wells and boreholes in the area, but relatively few of these are believed to have been captured by the PDB. A7.5 Conducting the surveys The majority of the survey area is urbanised, with land uses ranging from informal settlement, small and medium enterprises, commercial land including retail and service sectors, and tourist hotels; there is also a golf course. Consequently, these surveys would need to be designed on the assumption of extensive door to door visits, which is manpower-intensive and time consuming. Hotel and golf course boreholes, as well as boreholes serving shopping centres and formally-developed residential estates, are probably captured in the PDB. A7.6 Groundwater abstraction survey Standard equipment for groundwater abstraction surveys, both manual and electro-magnetic meter methods. Flow meters – if present – should be checked. A7.7 Groundwater quality survey Equipment for field chemistry (electrical conductivity, temperature and pH at a minimum) will be essential. Collect samples at a quarter of the sites visited will be tested for major anions and cations as well as specific seawater intrusion indicators (bromide, or strontium and boron). The groundwater quality survey may include bacteriological parameters (total coliforms and E. coli). This would significantly increase the cost and logistical complexity of the survey. A component part of a groundwater quality survey in the Kisauni context would be to visit and geo- reference all pit latrines, septic tanks and solid waste dumps in the area.