Diana L. Nichols

Diana Nichols is a partner in PLG’s Water practice. For the past decade, she has represented clients, including landowners, industrial users, developers, investors, utilities, and governmental entities, in matters involving water rights, water supply, water reuse, groundwater and surface water management, and related issues across Texas. Her work includes helping clients secure, protect, manage, and evaluate water assets.

Diana brings a distinctive litigation perspective to the firm’s water law practice. Before transitioning to water law, she spent more than twenty-five years as a trial lawyer handling high-stakes matters in state and federal courts, including environmental contamination claims, contract disputes, real estate conflicts, regulatory and constitutional issues, and other complex cases. Her experience spans every stage of a dispute, from early strategic counseling and mediation to arbitration, agency proceedings, judicial review, trial, and appeal.

Diana applies that litigation background to water law matters, helping clients assess risk, build persuasive records, and navigate permitting, enforcement matters, transactions, and disputes.  Her litigation perspective and broad-based legal knowledge are particularly valuable when water-related regulatory, transactional, and business decisions may later be tested in a contested case hearing, suit for judicial review, or lawsuit. Her trial experience helps her to be an effective advocate for her clients in any forum.

Diana’s recent work has involved water issues arising from large land transactions, groundwater development, surface water permitting, U.S. Army Corps enforcement issues, and water sales agreements and conveyances.  She has assisted clients with regulatory investigations and advocated for them in contested administrative proceedings and water-related litigation.

Clients value Diana’s ability to combine practical water law experience with the judgment of a seasoned trial lawyer. She helps clients pursue water supply and water rights strategies that are not only legally sound and commercially practical but also positioned to withstand scrutiny if challenged.

Representative Experience

• Represented large landowner in U.S. Army Corps enforcement action regarding construction of instream lake, delineation, permitting, mitigation measures including the placement of a conservation easement.
• Evaluated impacts of ongoing litigation on potential investment in large groundwater development project for private equity company.
• Second chair in successful, contested permitting proceeding for a Canadian company seeking to construct and operate a large Texas industrial project dependent on the use and protection of groundwater resources.
• Conducted due diligence and assisted with water-related agreements for a private-equity-backed midstream energy company in its approximately $500 million acquisition of groundwater assets and related water rights in the Permian Basin.
• Counsel in contested administrative proceedings before the Texas Commission on Environmental Quality involving environmental permitting, landfill development, mining operations, and aquifer exemptions, obtaining favorable outcomes for clients.

• Lead trial counsel representing an oil and gas company in a lawsuit in which it was alleged to have contaminated groundwater. Obtained summary judgment in favor of the company.
• Successfully represented an oil and gas company in a lawsuit claiming that the Environmental Protection Agency had violated the company’s constitutional rights by entering an emergency order requiring the company to clean up alleged groundwater contamination without the opportunity for a meaningful hearing.
• Lead trial counsel in a lawsuit for judicial review of a permit issued by the Texas Commission on Environmental Quality to authorize a new industrial plant. Obtained injunctive relief to prevent construction of the plant.