100
supply (less basins included), obtaining high, medium and low water demands, and high,
medium and low water supplies. This allowed to size the SUDS considered and the
pumping and treatment systems.
The criteria were defined based on the objectives for the Day Water project (Ellis et al.,
2004), which are those used in the French survey on SUDS (Martin et al., 2007). These
criteria were evaluated by the University’s Physical Resources Office (PRO) and the
university researchers. Within the criteria set were taking into account technical aspects
such as: hydraulic and environmental performance; management aspects such as:
compatibility with the University’s Developing Plan; and financial aspects such as: Net
Present Value (NPV) of the investment. The criteria’s weights were defined by survey
conducted by four PRO leaders of the University and five experts on water management.
The scenarios were evaluated with the set of criteria defined, in order to construct the
decision matrix with minimum, average and maximum assessments (Galarza-Molina et al.,
2012).
As a result of those projects, the University’s PRO decides to implement a first stage of the
project of RWH in PUJB campus in order to use the rainwater collected in the football field
and its green surrounding areas and the near parking lot. Is planned to use this water for
landscape irrigation and floor cleaning, but the samples taken shows that it overpass the
standards limits for Cd, Hg, Mn and Pb. Therefore, it was proposed a Constructed-
wetland/reservoir-tank system as a treatment.
The constructed-wetland is a horizontal subsurface flow (HSSF) wetland (Figure 1), and
the underlying gravel bed was built with different gravel sizes to minimize possible
clogging.
Figure 2. Constructed-Wetland/Reservoir-Tank System (Reservoir-tank Volume=+-145m
3
;
Superficial Area of the Wetland=85.12 m
2
) and Ultrasonic-Level Measuring Device (blue
dots).
In order to determine the system’s hydrological and hydraulic behaviour, five ultrasonic-
level measuring devices were installed (Figure 1left), with data collected since the end of
October 2013. These devices are distributed throughout the system: one at the entrance of
the settling tank, three in the middle of the wetland and the last one measuring the
reservoir-tank’s water level.
