This map from the San Jacinto River Regional Watershed Master Drainage Plan (SJMDP) shows historically flooded areas in our greater San Jacinto watershed. We have already had flooding in Montgomery County. Over the decades it's gotten worse.
In addition to historical flooding, 60% of Montgomery County will sink because of aggressive groundwater use. Since all stormwater drainage relies on gravity (we don’t use pumps to move rainwater), this will reduce the capacity for drainage systems to function as they were originally designed, leading to more flooding in the future. We are already at risk of flooding due to increased development and higher rainfall events (like Harvey, tax day, etc), so sinking from groundwater overuse will make it worse. This map is also from the San Jacinto River Regional Watershed Master Drainage Plan and shows damages from past large rain events. This kind of flooding is costly, not just to the victims of these floods, but to our community at large. Another impact from overuse of our groundwater is faulting.
FAULTING: As the ground sinks, faults are activated. Homes, roads and businesses located on these faults will be damaged by the unequal soil movement. You may have noticed road and foundation repairs in fault areas. There are numerous faults in Montgomery County: Navarro, Big Barn, Panther Branch and the Jones fault are examples - they've been documented in some scientific journals and or mentioned in local newspaper articles because of the damage they've caused to public buildings. We must be mindful of the consequences of subsidence and manage our aquifers accordingly.
REDUCED AQUIFER CAPACITY: When too much groundwater is removed from the aquifer, it compacts and is no longer able to hold as much water (it does not expand). If we continue on this path we will no longer be able to use as much groundwater and will be more dependent on more expensive surface water.
ESTIMATED COST: There is no official estimate for damage from sinking (how we can be selecting groundwater rules without knowing the damage the rules will cause!). To give a sense of the potential magnitude, by the time we have suffered the forecast sinking:
This is not the Montgomery County vision of the future! We need leadership NOW to prevent the sinking disaster in the future. While we all want cheap water, we should not be convicting future generations to a lifetime of higher taxes, higher flood protection costs, and lower property values.
WHY THIS MATTERS: Our homes, roads and businesses are structurally supported by the water underground, so if we use too much groundwater we cause our land to sink. Parts of Montgomery County have sunk one foot in the past 20 years, and some areas are expected to sink 3 MORE feet by 2080. This sinking is irreversible and causes damage to our homes, roads and businesses from flooding and fault activation.
OUR RECOMMENDATION: Rather than increasing groundwater use and risk irreversible and negligent subsidence, we should limit groundwater use to prevent subsidence, and ramp up use of surface water to meet growing demand.
TAKE ACTION: Please let LSGCD know what you think by email to firstname.lastname@example.org with the subject line “DFC Comments” no later than 11:59 p.m. on Jul. 19, 2021.