Wetlands Group
Problem 4: Where does the water go? --
Rice must find an effective way to hold back some of its stormwater.
Current Situation:
Because Rice is greater than ten acres in area, per city policy
the Harris County Flood Control District is required to sign off for all
new construction.
According to Walter P. Moore and Associates, who built Rice's
detention pond in 1987, the university may be required to detain approximately
.55 acre-feet of water per acre of footprint space made after 1986.
This standard was put into effect to help manage the local
flooding problems around this area of Houston, which heavy building (and
no place for stormwater to saturate into) has lately exacerbated.
Brays Bayou fills up quickly, sewers are under capacity on
campus and in Houston areas. As Rice and the surrounding community
continue to build and take up even more footprint space, we will have to
find ways to hold back even more in order to prevent sewage backflow from
the bayou (See Appendix D, Section 1)
Criteria:
Fulfill its outfall requirement
Maintain an aesthetically pleasing environment
Consider ecological and health side effects
Maximize benefit to natural community
Minimize economic cost (startup and maintenance)
Solutions:
Dry Detention Areas
A dry detention area is used to hold water during and immediately
after a storm event. It can then slowly release the water, either
through evaporation or drainage piping. They are advantageous in
that they allow water to be held back and can prevent overtaxing of the
watershed. Here at Rice, where Brays Bayou tends to flood from too
much runoff from Rice and other Houston sources, the ability to retain
some of the stormwater until after the bayou has had time to drain would
help to alleviate water problems both for Rice and nearby areas.
With a reduced flow rate, the water actually sent to the storm sewers will
drain more efficiently.
Figure 8; Detention Area
Detention Areas can be implemented in one or several areas
on the Rice Campus, including (See Appendix D, Section 2):
Expansion of current Walter P. Moore detention area
Construction of a multi-level parking garage
Wet Retention Ponds
One large wet retention pond for all of the campus runoff may
be more aesthetically appealing than a dry detention area.
Figure 9 A retention pond
A retention pond is a constructed pond that maintains a permanent
pool of water collected from stormwater runoff. Because they are
always filled with water (though the level varies) they tend to be more
pleasing. Retention ponds also allow for the creation of more green
areas. Additional funding for a retention pond can come from its additional,
functional uses (Appendix D, Section 3).
