Montebello Waste Water Lake Reservoir Report

Last Updated: December 5, 2025

Montebello Waste Water Lake, also known as Dam No.


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Summary

1, is a fascinating Earth dam located in Baltimore City, Maryland. Built in 1915 by designer James W. Armstrong, this dam stands at a height of 46 feet and spans 490 feet in length. With a maximum storage capacity of 110 acre-feet and a normal storage of 79 acre-feet, this dam serves a critical role in managing the Herring Run-TR-OS water system.

Despite its age, Montebello Waste Water Lake has a low hazard potential and is currently not rated for its condition assessment. However, regular inspections are conducted every five years to ensure its structural integrity and safety. The dam features an uncontrolled spillway type with a width of 6 feet, allowing for a maximum discharge of 915 cubic feet per second. As a state-regulated structure, it falls under the jurisdiction of the Maryland Dam Safety regulatory agency.

With its historical significance and important role in water resource management, Montebello Waste Water Lake offers a glimpse into Maryland's infrastructure development and environmental stewardship. Its moderate risk assessment level underscores the need for continued monitoring and maintenance to safeguard against potential hazards. As climate change impacts water resources and infrastructure resilience, this dam serves as a reminder of the ongoing challenges and opportunities in sustainable water management practices.

Year Completed

1915

Dam Length

490

Dam Height

46

River Or Stream

Herring Run-TR-OS

Primary Dam Type

Earth

Surface Area

7.2

Drainage Area

0.1

Nid Storage

110

Outlet Gates

Slide (sluice gate) - 0

Hazard Potential

Low

Foundations

Unlisted/Unknown

Nid Height

46
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.

Hazard Potential Classification

High
Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.