Watershed management is one of the most important
concepts to understand when seeking to improve the quality of our local
surface waters. A watershed is a drainage basin in which all land and water
areas drain or flow toward a central collector such as a river, stream,
lake, or estuary. The flow is propelled simply by land or stream elevation.
So, you might ask how large is the watershed for Tampa Bay? Interestingly
enough, the boundary of the Tampa Bay watershed encompasses portions of six
counties: Pinellas, Hillsborough, Pasco, Polk, Manatee, and even a tiny part
of Sarasota.
Watershed management is important to Tampa Bay
because any rainfall or discharge that occurs within the watershed boundary
will impact the bay and its tributaries. Thus, what occurs in parts of Pasco
or Polk counties can impact the Hillsborough or Alafia Rivers and eventually
Tampa Bay. On an even wider scale, the watershed for Florida includes a
large portion of western Georgia and eastern Alabama. Thus, planning and
acting regionally to protect water bodies is a concept based in science and
makes good public policy.
A regional approach is one reason why at the
Environmental Protection Commission (EPC) we place a high priority on
monitoring the water quality of Tampa Bay and many of its tributaries. Our
monitoring data have been used many times to make planning and permitting
decisions, and more recently to determine whether the Tampa Bay Water
Desalination Facility near Apollo Beach was impacting the salt balance in
nearby waters. Our data found that it was not. Our data have also been used
by local governments, private industry, the state, and the federal
government to evaluate the health of local waters and to measure the degree
of improvement in those waters when restoration projects are initiated. This
ensures that locally we are focusing our limited financial resources on
improving waters where it is most needed and that we are using restoration
techniques that have the greatest chance of success.
The Tampa Tribune recently highlighted an
excellent example of a collaborative regional effort using local data when
it cited the work of the Tampa Bay Estuary Program’s Nitrogen Management
Consortium, a group of over 30 public and private partners working to
improve water quality in Tampa Bay. This group has worked for over ten years
with the express purpose of cooperatively developing a plan of action to
meet nitrogen reduction/management goals for the bay and has collaboratively
defined pollutant load limits for each partner to support water quality
goals. Their efforts have been so successful that state and federal
regulatory agencies are considering their findings and proposals as new
regulatory limits for bay protection. This will be the first time nationally
that pollutant load limits have been developed by such a local cooperative
effort.
The National Research Council has said that
managing water resources at the watershed scale, while difficult, offers the
potential of balancing the many sometimes competing demands we place on
water resources. We are fortunate to not have to cross international lines
with competing interests as we manage our local resources to protect water
quality and ensure sufficient water quantity. In many parts of the world,
these are significant issues with huge economic and social impacts.
The Tampa area has changed greatly in the last
100 years from a community where central sewers in Tampa only first appeared
in the 1890’s and most of those just collected the wastewater to discharge
it directly to the Hillsborough River and Hillsborough Bay. It was not until
1950 that the first primary sewage treatment plant was completed. In a
period of only 60 years we have gone from no centralized wastewater
treatment to state of the art treatment and recycling at Hillsborough
County’s Advanced Wastewater Treatment (AWT) facilities and the City of
Tampa’s Howard Curren AWT Plant.
Today’s water quality issues are more subtle and
complex than the old “end of pipe” easily identifiable sources of
concentrated pollutants we faced in the past. Today’s environmental
management issues involve less visible pollutants such as high nutrients,
low dissolved oxygen, bacteria, and heavy metals. We do however see the
results of these pollutants since they may impact the growth of sea grass
beds, and lead to fish kills, beach closings, and fish consumption warnings.
Although the Tampa Bay community has made good
progress in meeting our target levels for nutrients, we still have much to
do with respect to other pollutants. In fact, the state has already
identified 177 segments of local waters that are impaired for a variety of
pollutants. Restoring our local impaired waters will take a lot of effort
and cooperation by all. Cleaning up these waters will be expensive and we
must approach it in an economically prudent manner. It only makes sense to
use a regional watershed based approach similar to that used by the Nitrogen
Management Consortium so that we may focus our limited resources toward
projects and solutions to enhance the water quality of these impaired
waters. Thinking in terms of the watershed will help us get to the best
solutions.
Water is recycled continuously in nature through the hydrologic cycle. It
leaves the earth's surface and enters the atmosphere through evaporation and
then returns to the earth through rainfall. When it does one of two things
happen. In a natural system, rainfall gently seeps through the soils and
eventually finds its way to underground storage aquifers where it may stay
for eons. This is where our well water comes from. The second natural path
of water is to slowly gravity-flow across the land surface making its way to
small streams and eventually to larger rivers and bays. Where this fresh
water enters bays or estuaries we find some of the most productive habitats
in nature. So in nature, we have pathways for natural replenishment of our
aquifers and for the maintenance of our productive estuaries.
What happens if either of these natural pathways is altered or
disrupted? Activities such as uncontrolled ditching or draining, paving,
deforestation, wetlands destruction, and channelization all serve to take
the water off the land and run it to the estuaries faster than in nature.
What this does is decrease the amount of water allowed to slowly percolate
into the aquifer, and dump water into the estuaries without its normal slow
cleansing flow through local wetlands. Thus, through unwise development
practices we can seriously negatively affect two important natural
protections of our waters.
So the best way to look at the hydrologic cycle and the flow of water off
the land and to rivers and estuaries is to think in terms of slow is better.
The more wetlands, either connected or isolated, large or small, that you
have to allow floodwaters to flow through, the better and cleaner the water
will be that eventually reaches the rivers, streams and bay. This also has
the side benefit of decreasing the volume of early stage floodwaters because
the flood flows have been captured by the wetlands systems.
All this is made even more significant when you consider that Florida and
Hillsborough County have lost about 50 percent of their wetlands. State
policy in the late 1800s and early 1900s was to ditch and drain, to dry up
the wetlands for developable land. Back then it was not appreciated that
these wetlands resources are hugely important in many ways; for floodwater
storage, storm buffering, recharge to groundwater, pollutant filtering, and
as habitat for fish and wildlife. In fact, Hillsborough wetlands contain the
state's largest breeding colony of roseate spoonbills and 50 percent of
Florida's white ibis nesting colonies. The colonial bird nesting sites in
Hillsborough are considered to have the highest species diversity in the
continental United States and the county's wetlands support at least nine
species of special concern as well as two threatened and one endangered
species.
Fortunately today in Florida there is a much better understanding and
appreciation of the need to conserve our remaining natural resources. There
are efforts under way through regulatory and cooperative restoration
projects at the federal, state, and local levels. Florida is a large state
encompassing numerous types of ecosystems. In Hillsborough, for instance,
more than 20 percent of our wetlands by number are comprised of small
isolated wetlands less than one half acre in size. This is partially because
of the unique geologic formations resulting in numerous small isolated
depressional wetlands.
All the more reason to have local protection.
