WATERSHED MANAGEMENT

Muhammad Tayyab Nauman2004- ag -1411

7th SemesterDepartment of Agronomy

Watershed

The area that drains into a river or other body of water. Actions in one part of a watershed will often have an impact throughout the watershed.

Watersheds & Watershed Management

A watershed is the total land area above some point on a stream or river that drains to that point.

Watershed management: process of organizing and guiding land and other resource uses on a watershed to provide desired goods and services without adversely affecting soil and water resources.

Concept recognizes interrelationships among land use, soil, and water, and upland-downstream linkages.

Watershed management encompasses the planning and utilization of watersheds. The term watershed refers to an area of land that drains water from precipitation or upstream watersheds to a common point such as a stream or lake. Precipitation falling on any part of a watershed can travel quickly on the surface of the land, known as surface runoff, or travel through the subsurface, which is a slower process. Once the water reaches the stream, it will travel through a complex network of streams until it ultimately reaches the ocean. Any sort of activity in a watershed, ranging from agricultural to urban, can affect the quality of water in and exiting a watershed. Thus, it is important that proper land management practices are used to ensure good water quality

Sources of pollution

In an agricultural landscape, common contributors to water pollution are nutrients and sediment. They typically enter the stream systems after rainfall events wash them off of poorly managed agricultural fields, called surface runoff or flush them out of the soil through a process called leaching. These types of pollutants are considered nonpoint source pollution because you can't identify the exact point from where the pollution originated. Point source pollution from livestock operations poses a potential threat as well if manure containment structures fail.

In urban landscapes, issues of soil loss through erosion, from construction sites for example, and nutrient enrichment from lawn fertilizers still exist. However, a few more must be considered as well. Point source pollution, such as effluent from waste water treatment plants and industries play a much larger role in this setting. Also, the greatly increased area of impervious surfaces, such as concrete, combined with the modern storm drainage systems, allows for unnaturally quick removal of the water from the landscape. However, any pollutants, such a lawn fertilizers, petroleum, etc., are also quickly removed along with the water and ultimately end up in the nearest stream.

How pollution is controlled In agricultural systems, common practices include the use of

buffer strips, grassed waterways, the reestablishment of wetlands and other forms of sustainable agriculture practices such as conservation tillage, crop rotation and intercropping. After certain practices are installed, it is important to continually monitor these systems to ensure that they are working properly in terms of improving environmental quality.

In urban settings, managing areas to prevent soil loss and control storm water flow are a few of the areas that receive attention. A few practices that are used to manage storm water before it reaches a channel are retention ponds, filtering systems and wetlands. It is important that storm water is given an opportunity to infiltrate so that the soil and vegetation can act as a "filter" before the water reaches near by streams or lakes. In the case of soil erosion prevention, a few common practices include the use of "silt fences", landscape fabric with grass seed and hydro seeding. The main objective in all cases is to slow water movement to prevent soil transport.

Federal Agencies and Their Roles in Watershed Protection

Federal agencies typically involved with the planning and continued monitoring of environmental improvement projects and generally responsible for compliance of several environmental laws such as the Clean Water Act. Assistance with watershed protection is also provided on a state level through Soil and Water Conservation Districts and other state operated departments (Department of Natural Resources, Department of Agriculture, etc.).

Beyond governmental support, other organizations and companies exist that provide support in various manners with the goal of watershed protection in mind as well.

By identifying desirable goals and outcomes, and ensuring that steps are taken towards those goals, planning can help society run more smoothly. Watershed planning refers to planning for the competing interests and goals that may be present in one watershed.

Also important are the laws that inform planning processes. Some require that planning be done, others can be used to make a plan legally enforceable and others set out the ground rules for what can and can’t be done in development (and therefore in planning).

Finally, those concerned about aquatic habitat protection have a right to participate in the laws and planning processes that affect aquatic habitats. By having a clear understanding of who to speak to and how to present the case for keeping our waterways clean a member of the public can become an effective watershed protection advocate.

Steps involved in watershed management

·         “Accessing Government” – A crash course to understanding government, law-making, planning and how to get involved in all of it as a watershed advocate. Good background for anyone who wants to influence government, whether on watershed issues or not.

·         “Issues and topics” – Identify watershed issues and problems and learn about what laws and planning processes apply to them. This is a great starting point if you’re concerned about a particular watershed issue, but don’t know much about the legal or planning requirements.

·         “Laws & Plans” – A description of every piece of legislation and planning processes that the Guide’s authors thought might be useful to those engaged in watershed protection. This section is useful if you know what law or planning process you want information about.

·         “Case Studies” – Learn by reading stories. The case studies set out common watershed protection issues and then tell a story about how local citizens used advocacy, legal and planning tools to work for watershed protection. You can then move from the case study stories to more detailed information about the tools used.

HYDROLOGY

“…the science of water that is concerned with the origin, circulation, distribution, and properties of waters of the earth”

Water will be a main Global NRM concern into the 21st Century

Water Scarcity Floods, Landslides, Torrents Water Pollution Scarcity of Land and Natural

Resources

Issues Threatening Sustainable Development Water Scarcity (UN 2003; Falkenmark 2003):

* By 2025 – 1/3 world’s population will face severe shortages of water * Irrigated agriculture uses 70% of all runoff used by humans* Requirements for agriculture will more than double by 2050* Large scale water development projects opposed for environmental/ecological reasons

Issues Threatening Sustainable Development (continued)

Floods, Landslides, Torrents: Billions of $ in damages worldwide each year

Example: Recent flooding in Sindh and Balochistan

http://sts.gsc.nrcan.gc.ca/tsd_dcp/app/imagerepository/32E0FAC0A574424E80A19D95C2C02002.jpg

Flood in the Indus River Valley

Floods and Debris Flows

Rainfall averages 2,500 mm/yr; in high elevations, rainfall is 3,000-4500 mm/yr

Averages three typhoons each year Landslides and debris flows are common in st

eep mountains and valleys Millions of dollars spent each year in flood pre

vention, forecasting & recovery

Landslides Add Material for Debris Flows

Disaster Mitigation Modifying Natural Systems with Extensive Use

of Engineering Measures Modifying Human Systems and Behavior is a

Viable Option Coping with Uncertainties of Extreme Natural

Events Public Information, Education and Participation

is Essential

Issues Threatening Sustainable Development (continued) Water Pollution (UN 2003): * 1/5 world’s population lacks safe drinking

water * More than 2 million die each year from

diseases due to polluted water & poor sanitation

Land Scarcity: In quest for food security, expansions in agricultural production will largely come from cropland expansion on forests & grasslands (Falkenmark 2003)

Need for comprehensive watershed management

• Recognizes linkages between uplands and downstream interests, and

• Facilitates development of sustainable management solutions to current land and water degradation problems

Concepts of watersheds as management systems are centuries old

Expanding human populations and increasing demands for natural resources make watershed management even more relevant today

IWM: What is it? Managing natural resources in a watershed

Focusing on land-people relationships in the context of water needs and supply opportunities

Involves both vegetative & structural changes Considering multiple spatial scales, from plot to

farm, to watershed and on up; Using cooperative management, not a single

mgt. Unit (thus, policy framework becomes critical)

Involving multiple stakeholders/participants

EXAMPLE

Land Use Impacts on Streamflow & Water Quality

Prairie Potholes Depressional wetlands found in the upper

mid-west and Canada More than half have been drained or

altered for agricultural uses

http://kulmwetlands.fws.gov/pothole.html

www.nrel.colostate.edu/.../ proj_51_land_use.html

Former wetlands

Watersheds

Globally, 80% of marine pollution is derived from land-based sources. Increased sedimentation/nutrients from

deforestation and agricultural practices.

Habitat destruction.

Urban/waste water run-off.

White Water to Blue Water (WW2BW)

To stimulate partnerships that promote integrated watershed and marine ecosystem-based management in support of sustainable development

Goal: