19. Technical Reports

This chapter addresses the content and structure of the technical reports that may be required as part of the development of a water conservation project. Technical reports should provide a concise and legible record of the findings, considerations and results of the site investigations, feasibility analysis, design, construction and operation and maintenance aspects of a project. This section is provided as a guide to ensure that critical elements regarding the documentation of a project are not overlooked. In addition, as many of the documents are required for regulatory authorities, consistency in regard to the structure of the document facilitates the assessment of the document by the regulatory authorities.

19.1 Site Reconnaissance Report

19.1.1 Introduction

The Site Reconnaissance Report provides documentation of the findings from the site visit and presents the conclusions and recommendations of the design engineer to enable the project owner to make the decisions required as to whether to proceed with the project to the next stage of investigations. The report is not a requirement for a regulatory authority.

19.1.2 Reconnaissance Report Outline

  1. Background and purpose of the proposed structure
    • Owner of the project;
    • Purpose of the project;
    • Location of the site;
    • Details and date of site visit.
  2. Findings from site visit and investigations
    • Land ownership and site access;
    • Project stakeholders;
    • Legal compliance aspects;
    • Topography;
    • Hydrology and sediment load;
    • Soils and geology;
    • Construction materials;
    • Environmental and social considerations.
  3. Analysis of alternative options
  4. Design issues
    • Limitations to scale.
  5. Construction issues
    • Approach;
    • Construction period;
    • Timing.
  6. Operation and maintenance/sustainability issues;
  7. Conclusions and recommendations
    • Does the professional conclude that the site(s) is suitable for the intended purpose?
    • What measures or steps should the project owner take to advance or alter the project to achieve the intended objectives?

19.2 Feasibility Report

19.2.1 Introduction

Once the feasibility assessment has been conducted and all relevant information collected, the design engineer should prepare a feasibility report. The information presented in this report will guide decision makers on whether or not to proceed with the proposed project to the design phase.

19.2.2 Feasibility Report Outline

  1. Executive Summary
    • Summary of project details and feasibility analysis. This is a concise summary of the key features of the project and can be used to share project details with project stakeholders like WRMA, WRUA, County government, community and potential development partners.
    • Summary of conclusions and recommendations regarding the economic, social, legal, technical, and environmental feasibility of the project.
  2. Background and purpose of the proposed structure
    • Owner of the project
    • Purpose of the project
    • Location of the site
    • Details of site visits and investigations
  3. Analysis of alternative options to meet project objectives;
  4. Analysis of water requirements to meet project objectives;
  5. Site investigations
    • Topography;
    • Soils and geotechnical.
  6. Environmental and social considerations
    • Scoping for EIA study;
    • Stakeholders;
    • Legal implications.
  7. Hydrological Analysis
    • Estimated inflow and design flood;
    • Risk of sedimentation.
  8. Identification of design issues
    • Criteria;
    • Estimated spillway sizes;
    • Offtake structures;
    • Ancillary structures.
  9. Project construction plan
    • Approach – labour based, mechanised, etc;
    • Project construction plan should identify the key steps and expected duration of the project going forward. It should cover the project from design through construction to certification.
  10. Cost estimate
    • A budget for each option should be produced based on the BoQ and estimated rates
  11. Economic analysis
    • A cost/benefit analysis should be conducted even if the scale of the project and the detail at this stage does not warrant a detailed analysis. However the total project cost, covering design, construction, supervision, and all environmental and social mitigation measures can be estimated. This may not reflect the true cost of all the impacts but assumptions regarding the estimation process can be described.
    • The benefits of the project should be described and estimated and compared to the costs. The intention is to avoid making investments in projects that cannot be justified due to the cost.
  12. Project financing
    • Identification of financing sources and issues.
  13. Analysis of risks and proposed mitigation measures
  14. Conclusions
    • Legal, social and environmental feasibility;
    • Technical feasibility;
    • Financial details/feasibility;
    • Economic feasibility
  15. Recommendations
    • Measures required to enable the project to meet its objectives;
    • Way forward.

19.3 Hydrological Assessment Report

19.3.1 Introduction

As per Section 27 of the WRM Rules (2007) WRMA may require a Hydrological Assessment Report prepared by a Qualified Water Resource Professional to accompany a permit application. The Second Schedule of the WRM rules (2007) sets out the outline of the Hydrological Assessment Report.

19.3.2 Hydrological Assessment Report Outline

  1. Name and details of applicant;
  2. Location and description of proposed activity;
  3. Details of climate;
  4. Details of river or water body (name, nearest river gauging station, sub-catchment);
  5. Details of catchment (area, slopes, soils);
  6. Details of vegetation and land use;
  7. Details of registered and non registered abstraction on the resource;
  8. Details of all other permits related to this application;
  9. Hydrological characteristics and analysis (annual, monthly, extreme events, flow duration or probability of events occurring);
  10. Hydrochemistry;
  11. Analysis of the reserve;
  12. Assessment of availability of flow;
  13. Impact of proposed activity on flow regime, water quality, other abstractors;
  14. Recommendations on proposed activity;

19.4 Environmental Impact Assessment

19.4.1 Introduction

A described in Chapters 4 and 6, the Environmental Impact Assessment (EIA) Report is part of the process to obtain an EIA license from NEMA and is applicable to the type of structures within the scope of this document.

19.4.2 EIA Report Outline

  1. Project description
    1. Project objectives/purpose;
    2. Location (GPS coordinates; grid reference);
    3. Nature and scope of project components;
    4. Expected benefits.
  2. Process of public disclosure and consultation
    1. Stakeholder analysis;
    2. Public meetings;
    3. Key informant interviews;
    4. Findings from public disclosure and consultation process.
  3. Project alternatives
    1. Alternative location;
    2. Alternative design;
    3. Alternative options to meet same objectives;
    4. No project alternative.
  4. Legislative framework
    1. Environmental laws and regulations;
    2. Other relevant laws and regulations - water, agriculture, livestock, forestry, fisheries, land planning, physical planning, land control, etc.
  5. Baseline situation
    1. Physical environment;
    2. Ecological environment;
    3. Social environment;
    4. Economic environment.
  6. Anticipated environmental and social impacts
    1. Pre-construction phase;
    2. Construction phase;
    3. Operational phase.
  7. Mitigation measures
    1. Pre-construction phase;
    2. Construction phase;
    3. Operational phase.
  8. Environmental monitoring and management plan
    1. Pre-construction phase;
    2. Construction phase;
    3. Operational phase.
  9. Recommendations

19.5 Dam Design Report

19.5.1 Introduction

The Dam Design Report is one of the requirements to accompany the water permit application. The outline provided below complies with the Water Resource Management Rules (2007) Section 64.

The dam design report should be complemented by the Environmental and Social Impact Assessment Report and the Hydrological Assessment Report as annexes to the design report. However, the main findings and results of the ESIA and HAR should be included in the Dam Design Report.

The dam design report presented below is customised to the case of a small earth embankment dam. The same report outline should be followed for other structures (mass gravity dams, pans, rock catchments, sand dams, sub-surface dams) but should be customised appropriately for the specific type of structure.

19.5.2 Dam Design Report Outline

  1. Executive Summary
    • Table of salient features
  2. Introduction
    • Dam name;
    • Physical location (grid reference);
    • Administrative location (county, sub-county,….sub-location);
    • Land reference number;
    • Drainage area;
    • Name of river or water body;
    • Class of dam and hazard assessment;
    • Owner of the land and structure;
    • Designer / engineer;
    • Dates: design completed, planned construction.
  3. Purpose

    Brief description of the purpose of the project and the expected benefits.

  4. Reference Drawings

    List of Reference Drawings, listing their subjects (titles) and reference numbers.

  5. Hydrological Assessment

    This information should be consistent with and drawn from the Hydrological Assessment Report.

    • Climatic conditions
      • Mean and monthly annual rainfall (mm);
      • Mean and monthly annual evaporation (mm).
    • Catchment features
      • Catchment area (km$^2$)
      • Longest path (length of river) in the catchment area (km)
      • Maximum altitude (m)
      • Altitude at the dam site (m)
      • Catchment conditions (land use, vegetation cover, slopes, soils)
    • Hydrological analysis
      • Description and quality of data used for analysis
      • Existing upstream and downstream abstractions
      • Hydrological characteristics (annual, monthly, extreme events, flow duration or probability of events occurring)
      • Reserve or environment flow requirements
      • Inflow design flows for specified return periods
  6. Assessment of Environmental and Social Impacts

    Brief description of the principal findings of the environmental and social impact assessment, covering both the short term (construction period) and long term (operational phase).

  7. Details of the Reservoir
    • Impounded area (ha);
    • Storage capacity (m$^3$), dead storage volume (m$^3$), net storage volume (m$^3$);
    • Expected annual evaporation losses (m$^3$);
    • Fetch (m);
    • Maximum depth (m);
    • Height-volume-area (HVA) curves.
  8. Details of Embankment
    • Height above lowest foundation (m);
    • Gross freeboard (m), minimum freeboard (m);
    • Dam crest: width (m), length (m), allowance for settlement;
    • Embankment slopes (h:v): upstream slope, downstream slope;
    • Core slopes;
    • Total Fill Volume (m$^3$);
    • Details of embankment fill: volumes and type of material of core fill (m$^3$), shell fill (m$^3$) filter material (sand, gravel) (m$^3$), rock-fill (m$^3$), rip­-rap (m$^3$);
    • Foundation excavation volume (m$^3$);
    • Upstream, downstream and crest protection measures.
  9. Details of Spillway
    • Inflow design flood (m$^3$/s) and return period;
    • Number of spillways;
    • Width(s) (m) and Lengths (m);
    • Number of sills, material and location;
    • Slope(s);
    • Excavation Volumes: Total excavation (m$^3$), rock excavation (m$^3$ ), common soil excavation (m$^3$);
    • Spillway protection measures.
  10. Details of Draw-off System
    • Brief description of the draw-off system and its principal components;
    • Diameter of draw-off pipe (mm);
    • Length of draw-off pipe (m) and anti-seepage arrangements;
    • Ground level and details of intake structure;
    • Outlet level at valve.
  11. Details of Scour or Compensation Flow Arrangement
    • Brief description of the scour or compensation flow arrangements and its principal components;
    • Diameter of pipe (mm);
    • Length of pipe (m) and anti-seepage arrangements;
    • Ground level and details of intake structure;
    • Outlet level at valve.
  12. Details of Ancillary Structures
    • Water level gauges;
    • Fencing;
    • Pump houses;
    • Valve chambers;
    • Consumer points (cattle troughs, water kiosks, etc).
  13. Catchment Protection Works
    • Brief description of the principal catchment protection works.
  14. Cost Estimate
    • Estimated construction cost (KES).
  15. Construction Schedule
    • Details of diversion works, if any;
    • Construction schedule.

    Figure 19-1 shows an elaborate example of a bar chart construction schedule for the construction of a new dam.

    Construction Schedule for Small Earth Dam

    Figure 19-1: Construction Schedule for Small Earth Dam

  16. Operational Rules
    • Description of operating rules;
    • Regime of environmental flow releases.
  17. Procedures to notify and protect downstream inhabitants, infrastructure and environments

    This material should be consistent with and drawn from the Dam Safety Plan (EAP).

    • Hazard risk analysis;
    • Notification procedures and details.
  18. Schedule of Inspection and Maintenance
    • Inspection schedule and details;
    • Maintenance schedule and details.

19.6 Dam Completion Report

19.6.1 Introduction

Section 66 of the WRM Rules (2007) requires the submission of a Dam Completion Report to WRMA. The report should be provided to the dam owner and users in addition to WRMA. The Report should be prepared by the engineer or technical staff involved in the project.

The outline of the Dam Completion Report, presented below, also meets the requirements of the Dam Operation Report as anticipated in Section 66 of the WRM Rules (2007). It is possible to submit one report that comprehensively addresses the as-constructed conditions and the operational aspects.

19.6.2 Dam Completion Report Outline

  1. General Information
    • Details of owner and dam users;
    • Location.
  2. As-Constructed Details
    • Technical design details, revised for as-constructed conditions
    • Changes between the original design and as-constructed conditions with an explanation for the changes;
    • The final as-constructed details should be clearly specified. Particular attention should be paid to aspects of the project that are buried and would be difficult to ascertain without proper documentation. Final HVA curves should be presented.
  3. As-Constructed Drawings
    • A complete set of as-constructed drawings should b included in the Dam Completion Report with particular attention to site bench marks, level monitoring pegs on the embankment (if any), water level gauges, and spillway crest levels, all of which are relevant to future monitoring of settlement of the embankment or changes to the as-constructed conditions over time.
  4. Operation and Maintenance Issues
    • Release rules, including releases for environmental flows;
    • Schedule of operation and maintenance tasks and responsibilities around dam, reservoir and catchment area;
    • Stocks needed to perform the maintenance tasks;
    • Schedule of monitoring tasks, including relevant forms and data management systems;
    • Schedule of inspection, including relevant forms, and remedial measures if needed;
    • Catchment protection.
  5. Emergency Procedures
    • Notification Flow chart drawn from the Emergency Action Plan;
  6. Recommendations
    • General recommendations on catchment conservation which may cover issues of overgrazing and soil conservation activities and
    • Means to control pollution of the dam.
    • Measures to minimise and manage water use conflicts, should they arise;

19.7 Emergency Action Plan

19.7.1 Background

The Emergency Action Plan (EAP) is an operational document that provides the agreed procedure and contact details for those responsible in the event of an emergency. It should be structured to enable quick and easy reference to key information.

19.7.2 Emergency Action Plan Outline

Title Page/Cover Sheet

Table of Contents

  1. Notification flowchart;
  2. Statement of purpose;
  3. Project description;
  4. Emergency detection, evaluation and classification;
  5. General responsibilities under the EAP;
  6. Preparedness;
  7. Inundation maps;
  8. Appendices;
  9. Investigation and analyses of dambreak floods;
  10. Plans for training, exercising, updating and posting;
  11. Site specific concerns;
  12. Approval of EAP.

19.8 Dam Failure Report

19.8.1 Introduction

Section 68 of WRM Rules (2007) requires that a report be submitted to WRMA in the event of a dam failure, regardless of whether harm or damage was caused downstream. This report provides documentation on the events leading up to and causing the failure. It is important that the document is prepared immediately after the dam failure as information regarding the cause of failure may be lost with time.

19.8.2 Dam failure Report Outline

  1. Details of dam location;
  2. Date and time of dam failure or damage;
  3. Preceding climate;
  4. Preceding hydrology;
  5. Cause of dam failure or damage;
  6. Steps taken to notify downstream inhabitants;
  7. Nature and extent of damage caused to the dam or caused by the dam failure;