South Florida Water Management District

Evaluating trends of historical rainfall on a weekly and seasonal basis is needed
for optimizing the design and implementation of lawn water conservation strategies like
outdoor water restrictions. While “day of the week” water restrictions are a typical
strategy to limit the frequency and duration of urban lawn water use, they may not
necessarily result in more conservative behaviors from end-users. Because weekly
rainfall and local climate variables are seldom taken into account in water restriction
strategies, they are not connected to actual lawn water demand. However, since lawn
water demand is directly related to weekly rainfall totals, not to a particular number of
watering days per week, water restriction schedules have the potential to unintentionally
promote overwatering. This study investigated the weekly patterns of average seasonal rainfall and evapotranspiration in South Florida to determine the typical variability of
weekly net irrigation needs and found that typical wet season weekly rainfall often
provides a significant amount of water to meet the demand of residential lawns and
landscapes. This finding underscores opportunity to reduce supplemental overwatering
in residential landscapes if watering guidelines were modified to recognize seasonal
average weekly rainfall in this region
This study also tested a rainfall-based water conservation strategy to determine if
providing residents with information about how local rainfall could promote more
effective lawn watering behavior than just water restrictions alone. Experimental
households reduced lawn water use by up to 61% compared to the control group by the
end of the study. These results demonstrate that the neighborhood “rain-watered lawn”
signs helped experimental study group households become more aware of rainfall as the
primary input of water to their lawns. This study also investigated the role that lawn
irrigation from self-supplied sources plays in the urban lawn water demand and
investigates how the lawn water use and lawn watering behaviors of households that
source from self-supply differ from those who source from the public supply.

Protecting Natural Resources, such as drinking water in terms of quality and quantity, is one of the missions of South Florida Water Management District (SFWMD). Water Supply Planning is one of the many projects at the Planning Department of the SFWMD, in which sixteen counties are analyzed to determine the most accurate population distribution for water supply distribution among the water utility companies. This thesis examines the current methodology which is used at the SFWMD, and addresses its shortcomings. It then introduces a proposed methodology, to improve population distribution analysis, by incorporating satellite imagery. Textural classification of satellite imagery will be used to extract residential neighborhoods from non-residential areas. The resultant residential areas, which is in the form of raster data, then will be converted to a vector coverage to be utilized as an additional source of data. Incorporating satellite imagery eliminates the assumption of homogenous population distribution, which the current methodology is based on and consequently, leads to a more accurate population distribution methodology.

The South Florida Water Management Model was developed to evaluate proposed alternatives for the south Florida regional hydrologic system. The degree of certainty of the computed system performance measures is required to correctly apply these measures for evaluation and selection of appropriate water resources policies and investments. Initially, a sensitivity matrix is defined which summarizes the model output sensitivity to incremental changes of key parameters. The method of singular value decomposition is applied to the sensitivity matrix to better understand relations between parameters and output variables. Finally, parameter uncertainty is compared to that of total predictive uncertainty of the system performance measures.