Elliot Seeto
USP 186 (FA’09)
October 29th, 2009
1st Draft of Research Proposal: Revitalizing San Diego’s Watersheds as
Sustainable Water Systems
Greening water infrastructure and utilizing regional watersheds to create a self-sustaining local
water supply for the San Diego region
A research proposal submitted to the Urban Studies and Planning Program
University of California at San Diego
October 29th, 2009
Elliot Seeto
UCSD USP Senior Sequence:
USP 186, Section A01
E-mail: eseeto@ucsd.edu
Abstract:
Supplying water for the San Diego metropolitan area is a crucial issue because of the
growing population’s increasingly dangerous overuse and dependence upon imported
water. However, current research suggests that through employing principles of effective
watershed management and green planning, properly harmonizing infrastructure with
natural hydrological systems opens the possibility for creating self-sustaining water
systems. Therefore with such optimization, SD’s local water sources have the potential to
meet at least a significant amount of water demand. This proposal will examine how
effective SD region watersheds can be at supplying water if they are optimized and
converted into alternative water sources. Research data on this will be gathered from
archival records, GIS mappings, and analyses of relevant agencies’ implementation and
management plans. This study will contribute to literature on sustainable development,
watershed management, and California’s water crisis. Results will be shared with urban
planners, governments, and water agencies—with the hope that these findings will be a
step for SD towards becoming self-sufficient in its water supply.
Key terms: sustainable development, green infrastructure, water self-sufficiency,
regionally integrated watershed management
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USP 186 (FA’09)
October 29th, 2009
Introduction:
Aside from the goals, motivations, and possible courses of action, the most basic
objective of this research project is to determine the true potential of the San Diego regional
watershed network to be tapped for water—perhaps enough water to provide for human
consumption needs throughout the whole metropolitan area. As of now it is highly doubtful that
most of these bodies of water possess the capacity to do so given their current state (NRDC,
2008); in fact, the conditions of many San Diego watersheds have become severely degraded due
to human activity over the years, and thus are no longer capable of recharging and retaining the
amount of water that they used to be able to. However, there is still hope that these damaged
watersheds can be restored to their former glory if the right preparations are made. This is where
the project begins to concern the watershed management and green infrastructure aspects.
It takes watershed-based planning and management to nurse these aquatic bodies back to
full health, and the integration of green infrastructure will help maintain them—even
supplementing their abilities. If implemented correctly, effective watershed management “allows
an adequate supply of water that is sustainable over many years.” (Heathcote 1998, 8) Thus,
theoretically the combined power of the restored watersheds should be able to provide more
water to the county; but because the water usage needs of San Diego and neighboring counties is
particularly high, even that amount still might not be enough to meet the sizable demand without
over-tapping. So if San Diego is to achieve water self-sufficiency, we must look towards green
infrastructure to stretch this existing water supply. There are a number of options for this end:
one such is replacing standard street pavement with pervious pavers, granting aquifers improved
recharge as well as reduction of non-point source pollution from runoff; additionally, greywater
and sewage can be reclaimed and then thoroughly treated to be recycled or returned to the
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USP 186 (FA’09)
October 29th, 2009
watershed; another example can be rainwater and runoff collection systems. Exploring these
possibilities for the sake of establishing a potential local, watershed-based, renewable supply of
water for San Diego County is the main goal of this research project.
For the sake of clarity: a watershed is a hydrological drainage basin that often consists of
a combination of a network of rivers, creeks, lakes, estuaries, wetlands, and underground
aquifers. These aqueous bodies function first as gathering points for precipitated water like rain
and snow, whether directly or through runoff. Second, almost all of the components of the
watershed eventually meet and drain at common points—rivers flowing toward the ocean for
example. Watersheds also generally have the natural ability to cleanse freshwater of toxins and
impurities as it proceeds along the network, whether from the chemical treatments of wetlands or
from the porous rock filtration of aquifers. These factors, in addition to being rich wildlife
habitats, are the reasons why watersheds are extremely valuable natural resources. In a worstcase scenario, a heavily damaged watershed will lose not only its capacity to support wildlife and
ability to filter water, but also will cause major disruptions to the regional hydrological cycle—
which in turn would negatively impact surrounding environments and local climate patterns.
Despite the critical role watersheds play in the Earth’s ecosystem, human activity has
greatly harmed their functioning. For example, the San Diego River is hardly how it once was;
throughout the history of human settlement, parts of it have been diverted, dammed, drained,
dumped in, developed over, and overgrown by non-native plant species (Manson, 2008). The
Colorado River is being tapped so heavily that it rarely even reaches the Mexican Sea of Cortez
anymore (EPA, 2003). Patches of land that once were a part of lush riparian habitats now exist as
dried-out chaparral, which happens to be the main fuel of arid Southern California’s massive
wildfires. (NRDC, 2008) Overall, humans have unwittingly destroyed crucial resources that can
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October 29th, 2009
prove valuable to themselves—Southern California is facing a water crisis and yet its water
resources are largely still abused and neglected—especially when we need these amenities more
than ever.
Conceptual Framework and Literature Review:
As previously mentioned, the basic objective of this project is to determine what needs to
be done to employ San Diego watersheds as local water sources, and the ultimate goal to this end
is to find a viable sustainable water system for the region to become water self-sufficient. The
primary motivation driving this investigation is the California Water Crisis, which is a growing
dilemma of water shortages that keep worsening. San Diego, and much of Southern California
for that matter, is especially vulnerable to this crisis. The San Diego Association of Governments
offers a brief explanation why:
“The San Diego region is a semi-arid environment, with a limited indigenous water
supply. Our region is therefore dependent on a mix of local supplies and the importation
of outside drinking water sources. These sources include water from the Colorado River,
as well as the Northern California Delta system.” (SANDAG, 2002)
Here one observes several factors as difficulties with water in San Diego: First, the semi-arid
climate dries out moisture more quickly, so lawns and swimming pools require even more water
than usual to maintain. Second, the supply of indigenous water is extremely limited when
factoring in the overall population, so water must be imported from elsewhere—the water
diverted from Northern California and Colorado canals. In fact, sometimes as much as up to 90%
of all water consumed by the San Diego metropolitan population comes from the canals (City of
San Diego Water Department, 2002). If something drastic were to occur at the distant source
points, there is not too much Southern Californians will be able to do about it. In addition the
constantly growing population creates an increasing demand for water consumption, which lately
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October 29th, 2009
has significantly reduced the available quantity for other populations downriver, such as Mexico
(CRB 2003); if this is the case, then San Diego is next to get short-changed.
The main strategy of previous and ongoing efforts to mitigate the impact of this water
crisis in San Diego is an extensive series of public water conservation campaigns. This strategy
includes such measures as reducing water consumption per capita, eliminating wasteful habits
and practices, upgrading infrastructure to be water-efficient, and maintaining water quality by
combating point-source pollution. These methods have their merits and address the crisis to a
degree; however, this is not a real solution due to constant growth being the fundamental root of
the problem (Bell, 1995). Thus even if water conservation efforts successfully reduce water
usage per capita, the surplus of water saved is still insufficient for future needs because the total
supply of water will stay fixed while the growing population’s water usage continues to increase.
So because the supply of imported water will continue to dwindle despite conservation efforts,
the only viable solution is to establish sustainable local water systems.
As a result of the aforementioned factors, San Diego must become self-sufficient in its
water supply through local sources so that it is prepared for the possibility of import canal cutoffs. Becoming self-sufficient for water also holds many benefits; for example, locally gathered
and produced water is much easier to observe and manage, and even costs much less due to
reduced shipping fees and less need for extensive transportation infrastructure (Bell, 1995). In
addition, local control over the resource also means that revenues stay within the region, which is
beneficial for those economies. And despite what SANDAG mentioned prior about the limits of
San Diego’s indigenous water supply, the use of local water is still not completely disregarded
because of the fact that the “extensive groundwater resources beneath the San Diego River
provide a cost effective and reliable water supply to four local water districts and the City of San
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October 29th, 2009
Diego.” (Project Clean Water San Diego, 2009) Further supporting this claim, it has been
measured that up to 30% of the water consumed by the population comes from groundwater
extracted from underneath the San Diego River Watershed (SCC, 2008). Combining this piece of
evidence with the knowledge that the San Diego River also happens to be one of the more
degraded watersheds in the region—one can infer that if the river was restored back to full health,
it would yield much more water. Then if this were applied to all of the region’s watersheds, there
is a great possibility for local sources to replace water imports. On the other hand, even if these
restorations and upgrades still do not make a real significant impact upon the overall water
supply, the effort should be worthwhile anyway because it will have relieved at least some
degree of water import dependence, as well as have provided other benefits.
So despite the chance of a relatively low yield of extra water, another reason why taking
the watershed approach is worthwhile is that San Diego can combine it with different alternative
methods and work out a piecemeal sustainable water system. Within the region, there have been
ongoing efforts focused on finding more alternative sources of sustainable water supplies
through greening infrastructure, but not centered on watershed management. One of the most
major projects for an alternative water source is the construction of reverse-osmosis seawater
desalination plants. Costs, externalities, and overall feasibility have already been considered and
researched, with solutions found to many of its implementation setbacks (Bell, 1995); as a result,
desalination research now has the most popular support as an alternative sustainable water source.
There is also research currently being conducted on “Toilet-to-Tap” programs, which function as
closed-loop systems of treating and reusing recycled water. These alternate efforts are well
underway and appear viable so far for being sustainable supplements to San Diego’s water
supply (CWA, 2002). These separate efforts need not be mutually exclusive in the end, since it is
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USP 186 (FA’09)
October 29th, 2009
entirely possible to combine them so that each different method contributes to the overall system
without the negative effects of overstraining any one source.
Although such desalination and water recycling programs are being researched and
implemented however, not nearly as much research has been conducted for this project’s option
of maximizing existing watersheds for potential water extraction. This is in large part because
implementing watershed management infrastructure such as eco-parks, bioswales, and restored
floodplains receives positive reception from members of the general public mostly on the basis
of aesthetic, recreational, and other such values: environmental beautification, outdoor recreation,
wildlife preservation, and increased property values (Easley et.al., 2002). On the other hand, if
watersheds and their associated infrastructure were recognized more as potential sustainable
water sources, then there would be much a much greater incentive to begin pursuing these new
developments as soon as possible, since the benefits will not be immediately realized, but rather
in the long run. No matter what the reason or efficacy level of water sustainability, all
possibilities for alternative renewable water supplies need to be investigated, and so this project
will focus upon this watershed approach that needs more research.
Research Design and Methods:
An abundance of peer-reviewed, scholarly analysis on this specific topic using watershed
management to create a sustainable water source is lacking because research in this particular
field is relatively new. Therefore the theoretical effectiveness of such measures cannot be
predicted with full confidence or supported by substantial real-world evidence, since these ideas
are largely untested and still in the early stages of implementation. As a result, the research for
this project must rely less on existing bodies of formal scholarly inquiry, and more on relevant
organizations, expert experience, planning documents, policy analysis, and new data collection.
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USP 186 (FA’09)
October 29th, 2009
The main units of analysis will be at the watershed level, because watersheds are discrete
environmental systems with physical limitations. Even though watersheds are linked to many
other natural cycles and systems on multiple levels, the fact that they are delineated by physical
constraints makes certain properties measureable. The San Diego region is comprised of twelve
separate watersheds, each of different sizes, populations, land uses, and volume of potable water.
For the sake of the study, assume optimal infrastructure will be in place for a centralized system
that distributes water evenly, and that all contaminated water that would have been useable will
be treated. Another variable factor in is the minimum amount of water that a watershed requires
to be considered in healthy shape, since each one is quite different as stated. Several strategies
will be employed to cover the different aspects of the project.
Because it is impossible to instantly implement the ideal management practices and
infrastructural changes to the watersheds or observe their long-term results, a number of indirect
methods will have to suffice. First, in order to roughly estimate the surplus amount of water that
will be generated through restoring the watersheds, we must uncover data on their current
approximate total volumes of water, and the average amount of rainfall over their areas—
whichever units can be consistently compared across all of the watersheds. Then to fathom an
idea of how they will appear after the restoration, we will seek out archival data on the amount of
water retained by the watersheds before human interference—when they were in optimal health.
One more consideration to make in measuring the harvestable amount of water from watersheds
is any additional contribution by related infrastructure—whether it is collected rainwater from
storm drains and pervious pavers or reclaimed water that is sent back into the system. Once these
values are figured out, the rough effectiveness of watershed restoration can be gauged by
comparing the new total harvestable amount of water with the amount that San Diego consumes,
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USP 186 (FA’09)
October 29th, 2009
and then further comparison will be made with the amount of water currently imported through
canals, as well as future growth patterns in water demand. Then for the sake of gauging the
viability of a combined sustainable water system, these figures will be compared with the
amounts of water produced through such other alternative efforts as desalination and toilet-to-tap.
If the difference in restored watershed quantities turns out to be negligible or insufficient
to directly extract water from regularly, then we must investigate different aspects of the
relationship. What is considered to be sustainable is highly susceptible to scale—for example,
certain ecosystems may easily accommodate a few hundred people easily, but any more than that
and it will start to collapse. Thus even though optimizing a watershed with green infrastructure
may not supplement enough additional water for human consumption, it may be instead just
enough to revive plants and wildlife. So even if there is not enough extra water to extract directly
for human use, the changes may have just enough of an influence to mitigate the effects of
climate change, which indirectly affects the overall useable water supply on a larger scale.
As an intern for the San Diego River Park Foundation, additional data and information on
watersheds in the region are easily accessible. By analyzing plans and policies provided by
development organizations and planning collaborators, cross-comparisons and past case studies
can be conducted in order to predict such effects as implementing certain management practices
or types of infrastructure. Geographical information systems are more tools which can be utilized
for mapping out and identifying key features of watersheds, such as separate bodies of water,
floodplains, reservoirs, aquifers, and terrain for surveying purposes.
Over the course of the next few weeks, this project will still be susceptible to many
changes depending on what additional data or research will be uncovered; or conversely, what
necessary data cannot be found. If investigating and measuring all twelve watersheds proves to
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USP 186 (FA’09)
October 29th, 2009
be overwhelming with too many confounding variables, then efforts will be focused upon a
single watershed, such as the San Diego River Watershed. In this case, the watershed’s potential
capacities will be compared with the population residing within its borders, and the project will
concentrate more on feasible application such infrastructural changes to all watersheds in the
region. Either way, the more specific variables, limitations, spatial dimensions, and concrete
methods will be determined no later than two weeks before the end of the fall quarter, so that a
feasible scope of this project’s focus will be figured out. Once this is completed, actual
measurements and original data collection may begin by the end of fall, lasting through the
middle of winter quarter. Conducting this research should not require any direct monetary cost to
complete. Any accrued expenses will probably be due to transportation fees for fieldwork and
research outside of campus. Otherwise, the bulk of research through the library, internet, and GIS
mapping remains cost-free.
Conclusions (Expected Outcomes/Deliverables):
The most basic objective of this project is to determine the San Diego regional watershed
network’s true ability to supply water. The full potential for this can be visualized through the
analysis of proper regional integrated watershed management practices, as well as the greening
of water-based infrastructure. Research will be aimed at determining the nature of the
relationship between these changes and attaining a sustainable water supply for use by the local
population—basically, by determining what management practices and infrastructure can
possibly optimize the functioning of a watershed in increasing its capacity for water storage, its
ability to retain water, and its capability of cleanse water. The ultimate goal for this end is to find
how this may contribute to a sustainable water system which would at least greatly assist San
Diego in becoming self-sufficient in its water supply. Incentives for achieving self-sufficiency
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USP 186 (FA’09)
October 29th, 2009
include decreased costs to consumers in the long run and the preservation of natural eco-systems;
however, the primary motivation behind this research is discovering ways to mitigate or even
avert California’s water crisis.
If there is such a connection, a deeper understanding can be reached on not only how the
regional watersheds function, but also about the real benefits and efficacy of related green
infrastructure, such as eco-parks and bioswales. If the research results yield data strongly
indicating that careful watershed management and green infrastructure actually increase and
maintain a local water supply to the point of being able to sustain much heavier consumption
than previously, then perhaps there is a possibility these findings can be adopted by planners for
the sake of creating sustainable watershed systems everywhere.
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USP 186 (FA’09)
October 29th, 2009
Bibliography:
Bell, Jim. 1995. Achieving Eco-Nomic Security. 2nd edition. San Diego, CA: Ecological Life
Systems Institute (ELSI).
California State Coastal Conservancy (SCC). 2008. San Diego River Watershed Data Collection
and Restoration Program: Implementation Plan. Oakland, CA.
City of San Diego Water Department. 2002. City of San Diego Long-Range Resources Plan.
Colorado River Board of California (CRB). 2003. California’s Colorado River Water Use Plan.
Glendale, CA.
Easley, Sarah; Redick, Leslie; Turnbull, Katie and Zhang, Wei. San Diego River Park
Foundation. 2002. San Diego River Park Conceptual Plan. San Diego, CA.
Environmental Protection Agency (EPA). 2003. US-Mexico Border 2012 Program.
2008. Water Recycling and Reuse: The Environmental Benefits.
Heathcote, I. W. 1998. Integrated Watershed Management: Principles and Practice. 1st ed. New
York: John Wiley and Sons, Inc.
Letey, J. 1999. Science and policy in integrated watershed management: a case study. Journal of
the American Water Resource Association 35: 603-608.
Manson, Bill. There is no San Diego River. San Diego Reader. Oct. 22nd, 2008: San Diego, CA.
Natural Resources Defense Council (NRDC). 2008. Hotter and Drier: The West’s Changed
Climate. New York, New York.
Project Clean Water San Diego. 2009. San Diego’s Watersheds. San Diego, CA.
San Diego Association of Governments (SANDAG). 2002. Water element. Regional Growth
Management Strategy. San Diego County, CA.
San Diego County Water Authority (CWA). 2002. Negative declaration: water. Distribution
Regional Growth Management Strategy, SANDAG. San Diego County, CA.
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