WATERSHEED

TASK OF FORESTRY INTRODUCTION

arranged for comply task of  nature conservation resources and ecosystem in second grade.

Instructor of course: Mr. Fahriza Luth, S.Hut.

Arranged by:

Rizki Nur Apriliani

K.13.11.0013

 

  

MAJOR OF FORESTRY SCIENCE
FACULTY OF FORESTRY

UNIVERSITY OF WINAYA MUKTI

TANJUNGSARI

2014

                                               WATERSHEED

HOW DOES THE WATERSHED WORK

Natural features and functions within a watershed influence the quality and prevalence of water resources, and determine the extent to which the natural system can moderate the effects of human activities. This chapter describes the natural processes that move water through the watershed and how these processes affect water quality. An understanding of these processes is essential in order to protect them and to manage demands on the system, so that valued water uses can be maintained.

Watershed Hydrology

A watershed represents a unique physical unit within which water moves continuously in a cycle that begins with rain or snow. Within the watershed landscape, plant leaves will intercept some rain and snow, where it will evaporate back into the air. Rainwater and melted snow may infiltrate the soil or flow overland to be stored temporarily in depressions, wetlands or lakes. Groundwater forms when surface water seeps through the soil to varying depths and collects in aquifers. Groundwater can remain stored underground and then re-emerge as springs or discharges to rivers, lakes or wetlands, within a period varying from a few days to thousands of years. Eventually, water flowing over the surface or through the ground makes its way into rivers and lakes, or is taken up by vegetation, where it evaporates or transpires to begin the cycle again (More 1969). Natural watershed characteristics, such as geology, climate, landform, soils, and vegetation influence the processes responsible for water cycling. Therefore, these characteristics help determine how much water is available as surface supplies in rivers or lakes, or as groundwater in aquifers.

Climate affects the watershed directly by the distribution of rainfall and temperature. Variations in rainfall can be described by the intensity and type of storms, which in part influence groundwater recharge, streamflow and flooding patterns. Light rainfall that extends over a long duration has more time to infiltrate the soil and replenish groundwater supplies. Alternatively, high intensity thunderstorms that deposit large volumes of rainwater in a relatively short period of time cause rapid overland runoff and flash flooding of rivers and streams. The shape of the land, determined by geology and weather, greatly influences drainage patterns. The density of streams and the shape of a watershed, in turn, affect the rate of overland runoff relative to infiltration. Soil types influence the rate of water movement. For example, finely grained soils, such as clays, have very small spaces between soil particles, inhibiting infiltration and thus promoting greater surface runoff. Conversely, coarse soils, such as sands, have larger pore spaces allowing for greater rates of infiltration and reduced runoff. Soil texture, structure, moisture holding capacity and local topography are important factors determining the susceptibility of land to erosion.

Vegetation plays many roles in the water cycle. It intercepts rainfall, impedes overland flow, and promotes infiltration. Vegetation also uses water for growth. All of these factors reduce the quantity of runoff to streams. Vegetation binds and stabilizes soil, thereby reducing the potential for erosion. Vegetation also stabilizes stream banks and provides habitat for aquatic and terrestrial fauna. Land use activities that affect climate, landform, soils, or vegetation also impact the natural distribution of water within the watershed landscape. Temperature increases expected over the next 20-50 years, associated with global climate change, are likely to cause more intense storms and longer periods of drought, which will affect the distribution of water resources within Ontario. Water shortages, extreme flood events, and a shift in natural habitats, among other things, are predicted. Activities, such as urbanization and agricultural practices, can alter the slope of land and channel form; pave over or compact soils; remove vegetation; and have many other effects. These effects all result in changes in the water balance. That is, they can change the proportion of rainwater that flows overland relative to that stored, evaporated, infiltrated, or taken up by plants and transpired.

THE NATURAL WATER CYCLE

Current Issues in Water Management

Growth

A major watershed issue in southern Ontario is keeping the watershed healthy (economically, socially and environmentally) while accommodating growth. Urban areas are progressively looking for additional surface and groundwater supplies. Increasingly, these supplies are being depleted by others or are being contaminated by pollutants. Growth management includes planning ahead for determining appropriate land uses, ensuring adequate water supply; protecting surface and groundwater quality; allocating water with consideration for long-term planned commitments to future water supply and the environmental needs; and planning growth with consideration for the river and groundwater system capacity to receive wastewater.

Surface water and groundwater quality

Water supply for both human consumption and for maintaining aquatic/fishing resources is dependent on maintaining adequate quality in surface water and groundwater.

Water allocation

Water allocation will become an increasing issue as growth proceeds. Increasing population and intensif ication of agriculture both result in an increase in water use. Instream demands include recreational and industrial uses (i.e., hydroelectric production, navigation). The aquatic ecosystem, including fisheries, wetland and riparian habitats, is also dependent on a sustainable supply of water for its existence.

River system capacity for wastewater

At a watershed scale, surface water is used to dilute effluent from sewage treatment plants and a variety of non-point sources of pollution. A watercourse’s capacity to assimilate contaminants is directly dependent on the quantity and quality of water available for dilution.

Contaminant Pathways and Treatment Processes

The water cycle serves as a pathway for the transport of natural and introduced materials that influence the quality of the water. However, there are natural purification processes operating within the watershed that help protect the integrity of water supplies and overall environmental health.

Types of contaminants

Inorganic compounds, pathogens, and organic compounds can harm water quality when present in excessive amounts. These contaminants can adversely affect the health of humans, fish and wildlife. Inorganic compounds include all compounds that do not contain carbon. Nutrients (e.g., nitrates and phosphorus) and heavy metals are two examples. Nitrates can cause problems in drinking water, because they become toxic nitrite within the digestive tract. Nitrite causes methemoglobinemia, or blue baby syndrome, which impairs the blood’s ability to transport oxygen. Phosphorus promotes plant and algae growth. Algae can taint the taste of drinking water and foul aquatic habitat. Certain heavy metals are toxic to humans and wildlife. Heavy metals include iron, cadmium, mercury, lead and others. Pathogens, including bacteria and viruses, are the leading cause of water borne disease outbreaks. Cryptosporidium, Giardia, and, well known, E. coli. 157, all cause illnesses and sometimes even death when consumed. Organic compounds include Volatile Organic Compounds (VOCs) like benzene, toluene, xylene; semi-volatile compounds like phenol and napthalene; PCBs and pesticides. Today’s pesticides

are generally less toxic and less persistent than those used in the past, but their presence in water is still a concern as they are thought to be linked to endocrine (hormone) disruption in humans.

HUMAN INTERVENTION IN THE WATER CYCLE

Potential sources

Many compounds and pathogens occur naturally in soil and water. Certain land use activities, however, can accelerate their release and introduce excessive concentrations of contaminants in localized areas. Sources of contaminants are referred to as either point or non-point. Point sources are easily identified because they usually come out of a “pipe”. Examples include sewage treatment plants, combined sewer overflows, industrial plants, livestock facilities, spills, and others. Non-point sources refer to widespread, seemingly insignificant amounts of pollutants, which cumulatively threaten water quality and natural systems. Examples of non-point sources include improperly managed septic systems; agricultural, forestry or mining practices; construction activities; careless household management, lawn care, as well as road, parking lot and other urban runoff.

Treatment processes

Physical, chemical and biological functions associated with natural watershed features work together to remove pollutants from water (Hammer 1992). Physical filtration and sedimentation of particles occurs as water flows overland through vegetation or percolates through soils. Dense vegetative cover, shallow grades, and porous soils enhance these processes. As sediment particles are deposited, so too are many other contaminants, such as metals, hydrocarbons and bacteria, that are removed by chemical adsorption to the sediment particles. Storage or temporary detention of water in ponds, lakes or depressions further enhances the opportunity for sedimentation of inorganic contaminants, and also allows time for die-off of bacterial or viral contaminants.Chemical reactions and biological decomposition may break down complex compounds into simpler substances. Through absorption and assimilation, plants can remove nutrients from the water to aid in their own growth.

Plants also take up other contaminants, such as heavy metals, binding them into woody material for long periods of time. A by-product of plant growth is oxygen, which increases the dissolved oxygen content of the water, air, and soil around it. Oxygen aids in aerobic bacterial decomposition of pollutants, as well as sustaining life for many organisms that in turn convert other pollutants to beneficial uses. Dilution, while not a true treatment process, is sometimes recognized as contributing to the assimilation of contaminants to acceptable levels within a watershed. The cleaner the water body is, the greater its potential assimilative capacity. The relative significance of each of these processes depends on the natural characteristics of the watershed, and on the degree to which sensitive natural features and their functions are protected from the adverse impacts of land use activities.

Effect of Watershed Processes on Water Supplies

All natural water cycling and water treatment processes within a watershed play a role in influencing the abundance and quality of water supplies. However, certain processes have a more direct effect than others. In Ontario, domestic water supplies are drawn from three primary sources: 1) groundwater, either via private wells or public communal wells; 2) river-based surface water; or 3) lake-based surface water. Groundwater supplies are directly affected by changes in the natural rates of recharge (infiltration) and groundwater use. However, even a plentiful groundwater supply may be lost if it becomes contaminated. Groundwater quality can be affected by a variety of land use practices, such as septic fields, agricultural operations, or underground storage tanks. Groundwater supplies are especially vulnerable to contamination

when high-risk land uses are located within prime recharge areas.

 Sustained baseflow and water levels in rivers and streams is dependent upon properly managed surface runoff and groundwater levels. River and stream water quality reflects the natural geologic setting of the basin. In southern Ontario, most streams are impacted in some way by land use activities that generate pollutants and runoff, and by loss of the natural filtering capacity of wetlands, forests and vegetated stream buffers. Increased surface runoff and streamflow can erode streambanks adding to the sediments and other contaminants already carried in the watercourse. Streams that receive groundwater discharge can also be impaired by contaminated groundwater. Similar to rivers, lake water levels are dependent upon properly managed surface runoff within the lake catchment and on groundwater levels. Nearshore lake water quality, while influenced by contaminant loads from the entire lake basin, is affected by contaminants carried down from local watersheds and from direct groundwater and surface water discharges to the lake.

Summary

This chapter describes the natural processes that move water through the watershed and affect water quality. The water cycle serves as a pathway for the transport of natural and introduced materials that influence the quality of water. The chapter describes the type of contaminants, the source, and the natural functions that work as treatment process to remove contaminants from the water cycle. The watershed processes influence the quantity and quality of water supplies drawn from ground water and surface water.

MANAGING THE WATERSHED

The Watershed Management Process

The watershed management process can be seen as a continuum that includes producing a plan, implementing the plan (act), monitoring the effectiveness of the plan, and evaluating and updating the plan. This seemingly simple process, illustrated in Figure 3.1, is often difficult and complex to carry out. Despite the difficulties, the process is valuable because it promotes a systematic and logical way of thinking and a framework for making decisions with regard to water and land use. This section briefly describes the process. The watershed partners (province, municipalities, conservation authorities, aboriginals, private water users, the various other interested parties and the general public) are involved in all aspects of the management process. The process can be used for relatively straightforward problems where only one or two participants are involved, as well as complex problems involving a number of partners and participants and a large degree of uncertainty.

Watershed Planning

Key issues and underlying interests should be identified as soon as possible in the planning stage. All affected stakeholders or partners should be consulted as early in the process as possible. Often this is done at the outset by creating an informal group. As the group develops a working relationship and purpose, a more formal structure is developed with a steering committee to clearly define roles and responsibilities for all partners. Partners should be prepared to help develop the watershed plan and implement the plan recommendations. Typical issues of interest relative to this paper are:

· water supply crises, inadequate supplies of surface or groundwater to meet present and future

  needs;

· pollution of surface and groundwater systems;

· harmful impacts on wetland and aquatic systems.

Creating a vision, goals and objectives

Once problems or issues are clearly defined, it is necessary to quickly establish a vision, goals, and obje ctives. The “vision” is the big picture of the desired state of the watershed in the future. This provides a focus for planning and a standard against which progress and management options can be measured. A simple vision for water supply/water quality purposes could be: “We want enough clean drinking water to supply all the needs of a growing community without compromising the health and sustainability of our waterways and forests.”

Goals are the specific states we must reach to improve ecosystem and human health in the watershed. Specific goals give the direction for improvement. Compatible goals for our vision would include:

· provide adequate water supply to watershed communities, while still providing sufficient water 

  for environmental concerns;

· restore, protect, and enhance water quality for water supplies and aquatic resources;

· protect and restore the natural resources (land, water, forest, and wildlife) of the watershed.

Objectives are the measures or targets toward achieving the specified goals. Finally, it is most important to achieve community consensus about the relative importance of the problems

or issues and the appropriateness of goals and objectives.

THE WATERSHED MANAGEMENT PROCESS

Getting the information together

Effective decision making within the framework of watershed management requires comprehensive understanding of the current state of the natural environment, its historical characteristics, societal values, and where possible, economic influences. Determination of the information required and the level of detail is based on the watershed issues. Watershed planning projects typically begin with a “background review and assessment of available information” in order to identify and initiate efforts to fill information gaps. The completed information base allows the participating watershed partners to have a common understanding of physical features, processes, and community issues that presently exist and once existed in

the watershed. This information provides the building blocks with which to create predictive models of the system to evaluate the impacts of proposed management options. Due to funding and time limitations, particular attention should be paid to collecting information needed to address the agreed upon issues.

The participatory process

Ontario’s legal and institutional division of water responsibilities among various levels of government and the common property nature of water requires participation from a variety of government, nongovernment, community, and private interests in decision-making. Through a participatory process, it is possible to:

(a) define the problems more effectively;

(b) access information and understanding that fall outside the scientific realm;

(c) identify alternative solutions that will be socially acceptable;

(d) create a sense of ownership for the plan or solution, which facilitates implementation (Mitchell, 1997, pp 155-156).

Therefore, a participatory process should be part of watershed management, particularly in the following phases:

(a) defining the issues, goals, and objectives;

(b) providing information to aid the understanding of watershed processes;

(c) evaluating options and alternatives in the formulation of the watershed plan;

(d) creating linkages, partnerships, and action plans for implementation.

While a participatory process may extend the time needed during the initial stages of analysis and planning, such an investment is normally “returned” late in the process by avoiding or minimizing conflict. For this reason, public involvement is encouraged as early and as broadly in the process as possible to be most effective (Smith, 1982).

A quarter of a century ago, public involvement was seen as unnecessary and superfluous, if not downright invasive, by many decision-making bodies. Decisions were made at the “top” by provincial and federal agencies with little input from those affected. Today the trend is towards a “bottom up” approach where decision-making takes place at the local level. Watershed management requires a marriage of both approaches. It means that those who implement actions must be directly involved. A shared, collaborative approach is required to ensure that implementation is carried out and that the management plan does not sit on a shelf. This requires government agency participation and support as well as strong community involvement.

Some examples of successful participation and collaboration dealing with water supply and water quality issues include:

1. The Grand Strategy – building on the 1982 Grand River Basin Study, a multi-agency study dealing with water supply, water quality, and flood issues, The Grand Strategy, co-ordinated by the Grand River Conservation Authority, provides a forum for partners (municipalities, community groups, agencies, schools, businesses, and others) to pool resources, determine priority actions and celebrate successes. As part of this process, water managers within the watershed meet regularly and progress is being made toward updating the Grand River Water Quality Model, first developed as part of the Basin Study, and comple ting a water budget and water supply strategy.

2. The Torrance Creek Subwatershed Study – undertaken by the City of Guelph, in co-operation with the Grand River Conservation Authority (GRCA), this study investigated the best means of developing the creek without impacting both existing city groundwater supplies, and environmental features such as wetlands. The watershed steering committee included city representatives, developers, golf course owners, and various citizens' groups.

3. The Maitland Watershed Partnerships (MWP) – initiated by the Maitland Valley Conservation Authority, 34 organizations and agencies with an interest in resource management have formed a steering committee to examine best management approaches to managing water, agriculture and forestry.

Developing the watershed plan

Once the watershed goals and objectives are clear, tools are then developed to design and evaluate workable management options for achieving the goals. Management options may include measures that use technology or structures (sometimes called structural methods) and those that rely on changes in human behaviour or management practices (sometimes called “non-structural” measures). Generally speaking, structural measures such as treatment plant improvements are easier to implement, although considerably more costly than non-structural measures. Non-structural measures, for instance, encouragement of crop rotation and the installation of vegetated stream buffers, tend to be inexpensive but are difficult to implement

because people must change entrenched behaviours. Most watershed management strategies include a mixture of structural and non-structural measures designed to meet the issues of a particular watershed. For instance, options that are typically explored to increase water supply are:

(a) increased ground water supplies, from existing or new sources;

(b) surface water withdrawals from local sources or by pipeline;

(c) construction of surface water reservoirs and/or utilization of groundwater storage through

      recharge or infiltration schemes;

(d) control of water demand by water conservation, programs, etc.

Similarly, to deal with the contamination of ground water aquifers and surface water streams one could implement preventative measures such as:

(a) land-use controls to establish groundwater protection areas;

(b) controls of rural and urban non-point sources of pollution;

(c) increase levels of treatment at sewage treatment plants; or reactive measures such as increases

            in the level of treatment at water treatment plants. With the assistance of the watershed partners, various projects or options are combined into management alternatives to meet the goals and objectives of the watershed planning process. These alternatives are then evaluated to determine their effectiveness, costs, benefits, and environmental and social impacts. Modern computer technology greatly facilitates this task. Several tools used to screen and evaluate the

effectiveness of various alternatives include: For water supply alternatives:

· flow simulation models for both surface and groundwater,

· water budget models. And for water quality alternatives:

· stream water quality model,

· land use water quality model.

Appendix A briefly describes some of the evaluation tools.

Management alternatives are evaluated under present and future scenarios. It is particularly important at this final stage of plan development that the public and interested agencies have an opportunity to comment on the strategies being tested and to recommend different strategies for evaluation. After due consultation, a preferred management alternative is selected. This alternative is the basis for the watershed plan, which stipulates what actions are needed to accomplish the objectives. Time frames, costs, and responsibilities for implementation are also stipulated in the plan.

Action recommendations specify the work needed, the desired result, technical and staffing needs, costs, and a follow-up review for the effects of the action. Recommendations include the logical sequence in which the remediation takes place (e.g., undertake upstream work before downstream work, ensure that cattle access is restricted before repairing stream banks). Phasing of actions allows time to acquire funding for some parts of the project, provides a logical progression for improvement, or fits actions into future agency work plans. Some actions should be identified that are relatively easy to complete in a short time to provide incentive and encouragement for future work.

Risk assessment

Rather than relying only upon end-of-pipe solutions (increased levels of treatment) to reduce the risk of human exposure to contaminants, the watershed approach advocates preventing problems by controlling their source using various best management practices. Thus risks are diminished and the water supply system reliability may be improved. In planning studies dealing with risk, a key question is, “how much are the risks reduced by source controls?“Risk assessment” and “risk management” are procedures that recognize and incorporate elements of uncertainty in the evaluation of alternatives for protecting water supplies. These procedures provide a logical structure to make decisions determining which protective measures are most effective at reducing the risks to acceptable levels. They can be applied to help develop general watershed management policies and to evaluate site-specific water supply conditions for a particular community. Risk assessments for water supply questions utilize technical information to characterize the magnitude of human health risk. There are three elements of a problem that are relevant to risk assessment. These are:

· A source of contamination exists.

· One or more pathways exist, by which the contaminants may migrate to the well.

· One or more water consumers use the well and may experience health problems from  

  contaminated drinking water.

Appendix B provides a more detailed explanation of risk management and responses that may be used to reduce human health risk.

Implementing the Plan

Watershed plans are implemented through a variety of tools that are administered by several agencies at the provincial and local level. These tools can generally be categorized under the headings of land use planning, water and wastewater master planning, water resource regulations, land and water stewardship programs, public land acquisition programs, infrastructure development and maintenance, remedial measure programs and other operational activities. The province, municipalities, and conservation authorities will implement the watershed plan if they have been actively involved in developing the plan and if it is socially and economically practical as well as environmentally sound.

Only a small percentage of industries and landowners will take an interest or become involved in deve loping a watershed plan. The “What’s in it for me?" attitude will vary greatly among interest groups, stakeholders and the public, so a range of incentives are required to reach various people. Some just need information; some respond to recognition and applause or to peer pressure; and some may actually participate in order to avoid the courts. The incentives for participants should include education, information, opportunities to participate in planning or “hands-on” action, applause and celebration, cost-sharing incentives, public-private partnerships, and finally, surcharges, regulation, and enforcement (Minshall, 2000). The benefits of an approach employing this range of incentives rather than the traditional regulation and enforcement approach include reduced effort to cause change, longer-lasting change, and broader public support. In order to gain support for protecting drinking water sources, it is important to involve and educate citizens

to protect drinking water and the environment in general. Programs such as the Annual Children's Ground Water Festival are held each year in the Regional Municipality of Waterloo, Peel Region and commencing in the Saugeen River watershed in 2001. This festival helps children and their parents learn about the nature and value of groundwater.

The Yellow Fish Road program is another initiative that encourages stewardship and promotes awareness of the connectivity of urban storm drains with local creeks and rivers. Landowner stewardship programs help improve the landowners' management practices for their properties. The soil and crop improvement associations, conservation authorities, and the stewardship councils sponsored by the Ministry of Natural Resources all have various programs in this regard. Led by municipalities and public interest groups, promotional campaigns to reduce water demand through water conservation methods have been effective in the Grand River watershed. Canadian Heritage River designations of the Grand, Humber and Thames rivers, coupled with river-focussed tourism campaigns have made the public aware of the rivers as an environmental, economic, aesthetic and recreational asset, not as the glorified sewer of past eras. Conversion of abandoned railways running beside the Grand River into recreational trails for hikers and bicyclists increased the visibility and awareness of the river.

BIBLIOGRAPHY

Ashendorff, Arthur, Michael A. Principe, Anne Seeley, John LaDuca, Larry Beckhardt, Walter Faber Jr., and Jeff Mantus (1997) “Watershed Protection for New York City’s Water Supply” in Journal AWWA, Volume 89, March, pp. 75-88.

Adler, Robert W. (1996). Addressing Barriers to Watershed Management in Proceedings Watershed ’96, “Moving Ahead Together” Technical Conference and Exhibition, June 8-12, 1996, Baltimore, Maryland summarized from Environmental Law, Volume 25, pp. 973-1106 cited in <http://www.epa.gov/owow/watershed/Proceed/adler.html>

Alberta Environment (1999) The Framework for Water Management Planning A Discussion Draft, June 9, <http://www.gov.ab.ca/env/water/legislation/Framework.pdf>

Committee on Watershed Management, Water Science and Technology Board, Commission on

Geosciences, Environment, and Resources, and National Research Council, (1999) New Strategies for America’s Watersheds” Executive Summary, Washington, D.C.: National Academy Press, <http:/www.nap.edu/html/watershed_strategies/>